ASPEN TECHNOLOGY INC /MA/
10-K, 1997-09-29
COMPUTER PROGRAMMING SERVICES
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<PAGE>   1

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                    FORM 10-K
      FOR ANNUAL AND TRANSITION REPORTS PURSUANT TO SECTIONS 13 OR 15(d) OF
                      THE SECURITIES EXCHANGE ACT OF 1934

            [X] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                     FOR THE FISCAL YEAR ENDED JUNE 30, 1997

                                       OR

         [ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                         Commission file number 0-24786

                             ASPEN TECHNOLOGY, INC.
             (Exact name of registrant as specified in its charter)
         MASSACHUSETTS                                  04-2739697
  (State or other jurisdiction of        (I.R.S. Employer Identification Number)
  incorporation or organization)

                 TEN CANAL PARK, CAMBRIDGE, MASSACHUSETTS 02141
     (Address of principal executive offices)            (Zip code)
                                 (617) 949-1000
              (Registrant's telephone number, including area code)

           Securities registered pursuant to Section 12(b) of the Act:
                                      None.

           Securities registered pursuant to Section 12(g) of the Act:
                     Common Stock, par value $0.10 per share

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the Registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days: Yes _X_   No __.

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III to this Form 10-K or any amendment to this
Form 10-K.

The aggregate market value of the voting stock held by non-affiliates of the
Registrant as at September 19, 1997 was $654,185,862 based on a total of
19,823,814 shares held by non-affiliates and the closing price reported on the
Nasdaq National Market on that date, which was $33.00.

Number of shares outstanding at September 19, 1997:
21,087,628 shares of Common Stock, par value $0.10 per share.

                       DOCUMENTS INCORPORATED BY REFERENCE
The registrant intends to file a definitive Proxy Statement pursuant to
Regulation 14A within 120 days of the end of the fiscal year ended June 30,
1997. Portions of such Proxy Statement are incorporated by reference in PART III
of this report.
<PAGE>   2
                             ASPEN TECHNOLOGY, INC.
                          1996 FORM 10-K ANNUAL REPORT
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
PART I                                                                             PAGE
                                                                                   ----

<S>                                                                                <C>
Item 1.      Business                                                                2

Item 1a.     Risk Factors                                                           10

Item 2.      Properties                                                             13

Item 3.      Legal Proceedings                                                      13

Item 4.      Submission of Matters to a Vote of Security Holders                    14

Item 4a.     Executive Officers of the Registrant                                   14

PART II
Item 5.      Market for Registrant's Common Equity and Related
             Stockholder Matters                                                    17

Item 6.      Selected Financial Data                                                17

Item 7.      Management's Discussion and Analysis of Financial
             Condition and Results of Operations                                    19

Item 8.      Financial Statements and Supplementary Data                            25

Item 9.      Changes in and Disagreements with Accountants  on
             Accounting and Financial Disclosure                                    26


PART III
Item 10.     Directors and Executive Officers of the Registrant                     26

Item 11.     Executive Compensation                                                 26

Item 12.     Security Ownership of Certain Beneficial Owners and
             Management                                                             26

Item 13.     Certain Relationships and Related Transactions                         26

PART IV
Item 14.     Exhibits, Financial Statements Schedules, and Reports
             on Form 8-K                                                            27

SIGNATURES                                                                          29
</TABLE>

                                       1
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                                     PART I


ITEM 1. BUSINESS
           Aspen Technology, Inc. (the "Company" or "AspenTech") is a leading
supplier of off-the-shelf software products and services for the analysis,
design and automation of manufacturing facilities by companies in the process
industries, including the chemicals, petrochemicals, petroleum, pharmaceuticals,
pulp and paper, electric power, and food and consumer products industries.
Process manufacturers use AspenTech's solutions, a family of software products
and services, to design, operate and manage manufacturing processes more
efficiently, safely and profitably.

           AspenTech provides a sophisticated, integrated family of
off-the-shelf software products for use across the entire process manufacturing
life-cycle, from "off-line" applications used primarily in research and
development, and engineering, to "on-line" applications used principally in
production. The Company's off-line software is used by engineers on desktop
computers primarily to simulate and predict the performance of manufacturing 
processes in connection with the design of new facilities or processes and 
the analysis of existing facilities or processes. AspenTech's on-line software, 
which is connected directly to plant instrumentation, enables the real-time 
adjustment of production variables in response to constantly changing 
operating conditions to improve process efficiency, planning and scheduling. 
AspenTech's product offerings are classified in four categories: modeling; 
planning and scheduling; information management systems ("IMS"); and advanced 
process control ("APC") and optimization. Chemical engineers who work in the 
off-line research and development and engineering stages of plant and 
process design and analysis are the principal users of modeling products, 
while chemical and control engineers who work in the on-line stages of 
real-time plant operation are the primary users of IMS, APC and optimization 
software and services.

           The Company's modeling software mathematically simulates and predicts
the performance of manufacturing processes under varying equipment
configurations and operating conditions, enabling chemical engineers to design
cost-effective, efficient processes that comply with environmental and safety
requirements. AspenTech's planning and scheduling software is used by petroleum
refiners and chemical manufacturers for feedstock selection, product mix
optimization, logistics, scheduling, process unit optimization, and investment
planning. AspenTech's IMS software is used by process manufacturers to gather
and analyze large volumes of real-time plant operations data in order to better
understand actual performance within a complex process manufacturing facility.
IMS software allows customers to compare actual performance with theoretical
benchmarks derived from models and to make appropriate adjustments on a
real-time basis. AspenTech's APC and optimization software products are designed
to enable customers to achieve superior operating performance by continuously
adjusting key process variables to maintain optimal target levels under
constantly changing conditions. The Company initially became a provider of IMS
software and services through its acquisition of Industrial Systems, Inc.
("ISI") in May 1995, and expanded its IMS capabilities through its acquisition
of Setpoint, Inc. ("Setpoint") in February 1996. AspenTech significantly
enhanced its APC and optimization software offerings through the Setpoint
acquisition as well as its acquisition of Dynamic Matrix Control Corporation
("DMCC") in January 1996. AspenTech further extended family of on-line
solutions to include economic planning and scheduling capabilities by acquiring
the assets of Bechtel Corporation's PIMS (Process Industries Modeling System)
business in December 1996.

           AspenTech combines its integrated family of off-the-shelf software
products with design and implementation consulting services in order to market a
complete solution to its customers. The Company significantly strengthened its
on-line consulting services through its acquisitions of DMCC and Setpoint in
early 1996, and expanded the global reach of its consulting services
organization with the acquisition in October 1996 of the process control
division of Cambridge Control Ltd ("Cambridge Control"). AspenTech believes its
ability to offer a complete solution of both industry-leading software and
sophisticated process engineering expertise is an important source of
competitive differentiation.

           AspenTech's customers span a broad range of process industry
segments. With more than 750 customers worldwide, AspenTech currently licenses
its software to 45 of the 50 largest chemical companies in the world and 18 of
the 20 largest petroleum refiners in the world.


INDUSTRY BACKGROUND
           Companies in the process industries manufacture products such as bulk
solids, liquids and gases through operations involving chemical reactions,
combustion, mixing, separation, and heating and cooling. The process industries
include the chemicals, petrochemicals, petroleum, pharmaceuticals, pulp and
paper, electric power, and food and consumer products industries. Based on data
provided by industry trade groups, the Company estimates that the aggregate
worldwide revenues of the process industries exceed $3 trillion, of which the
chemicals industry has revenues that exceed $1 trillion and the petroleum
segment has revenues in excess of $500 billion.

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           In recent years, several factors have dramatically affected the
competitiveness and profitability of many sectors of the process industries.
Companies in certain process industries, particularly the chemicals industry,
have experienced intensified global competition, especially from competitors
located close to raw materials sources. In addition, companies in many of the
process industries face more stringent environmental and safety regulations.
These competitive and regulatory factors, as well as cyclical economic
conditions, can have a significant negative effect on the revenues and profits
of process manufacturers. Furthermore, while labor-intensive businesses can
respond to difficult business conditions by downsizing their workforces,
capital-intensive process manufacturers must focus on improving their production
processes. Therefore, in order to significantly reduce costs and increase
profitability, a process manufacturer must design, manage and operate efficient
and cost-effective production processes. In response to competitive, regulatory
and economic pressures, companies in the process industries are adopting
increasingly sophisticated off-line and on-line tools and methodologies to
improve the performance of their facilities.

           Chemical engineering analysis is the fundamental discipline behind
the improvement of production processes. Due to the number of variables
involved, chemical engineering analysis is complex and calculation intensive.
Without the use of process modeling and plant automation software, time and cost
constraints force engineers to make simplifying assumptions that may limit the
potential improvements to production processes. These constraints may also force
engineers to evaluate only parts of the process rather than the whole, or to
consider fewer alternative solutions. Process modeling and plant automation
software enables engineers to perform these complex calculations simultaneously
in order to arrive at better solutions quickly.

           Sophisticated software tools for off-line use that can accurately
model a broad range of processes have been available to chemical engineers since
the 1980s. Although early versions of the tools required substantial modeling
expertise and were limited in scope and complicated to use, in recent years the
availability of affordable, powerful desktop computers and intuitive graphical
user interfaces has expanded the market of potential users of process modeling
software. Moreover, process modeling software can now reliably model highly
complex chemical processes, broadening the scope of projects where its use is
applicable. These software tools can generate savings significantly in excess of
their cost by enabling users to design manufacturing processes with lower raw
material usage, decreased energy and capital equipment costs, improved product
quality and operating safety, cost-effective regulatory compliance and enhanced
engineering productivity. As a result of this improved availability,
functionality and cost-efficiency, many companies that previously relied on
internally developed models are adopting software products developed by third
parties who are better equipped to maintain and enhance these increasingly
complex tools.

           The use of off-line technology has been complemented by an increasing
demand for on-line applications for several reasons. First, the economic rewards
for making even small improvements in plant efficiency and safety can be
substantial. Second, the benefits of integrated process modeling, information
management, process control and optimization techniques are becoming
increasingly understood by customers. Third, while sophisticated tools and
expertise have not heretofore been widely available, commercial providers are
emerging to address these needs. Recent significant advances in software and
hardware technology, including the availability of more sophisticated
optimization algorithms and updatable graphical user interfaces, have made
on-line applications increasingly feasible for a growing number of process
manufacturers.

           In recent years, there has been increasing demand for integration of
all manufacturing processes from research and development to design,
engineering, and process and manufacturing management. Customers are looking to
the advantages which integrated on-line and off-line applications can bring to
their management of all process manufacturing activities. This is similar to the
integration by enterprise resource planning ("ERP") vendors of financial,
materials management, production planning, human resource management, sales, and
accounting applications. Commercial providers are emerging to offer tools and
expertise to further connect this technology layer which consists of integrated
design, control and management applications for process manufacturing ("Smart
Manufacturing Systems") with the ERP applications and the distributed control
systems ("DCS") which control the plants.

           As a result of the market dynamics in the process industries and the
rapidly evolving technology available to improve manufacturing processes,
process manufacturers increasingly seek a complete, integrated family of
software and services that can be used to design, operate and manage their
production processes more effectively.


THE ASPENTECH ADVANTAGE
           The Company believes it is the largest independent supplier of
software and service solutions used by companies in the process industries to
design, operate and manage their manufacturing processes based on fundamental
chemical engineering principles. AspenTech offers its customers in-depth
technical expertise encompassing both off-line and on-line applications. By
combining its traditional process modeling and optimization capabilities with
acquired skills in economic planning and scheduling, IMS and APC, AspenTech has
created a complete solution designed to provide several key advantages to
customers.

           Family of Products Across Full Manufacturing Life-Cycle. AspenTech
believes that it offers the most complete family of process modeling and plant
automation software tools used across every stage of the production process,
from research and development to engineering to production. The Company's
software products are designed to achieve improved process efficiency through
comparison of off-line predictive models with actual on-line production data and
through real-time adjustments to operating


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parameters in response to constantly changing conditions. The Company has
significantly integrated its on-line applications and intends to continue
integrating and enhancing both on-line and off-line applications.

           Complete Software and Service Solution. Customers increasingly
require expert consulting services to take full advantage of the highly complex
software tools being designed for the process industries. AspenTech deploys what
it believes is the largest independent organization of control engineers to
design and implement solutions, in combination with IMS, APC and optimization
software products. AspenTech believes its ability to offer its customers a
complete solution will be an increasingly important source of competitive
differentiation.

           Process Industry Expertise. Over the past 16 years, AspenTech has
built a reputation as a leader in process modeling expertise. AspenTech's
software products incorporate proprietary solution methods, physical property
models and data estimation techniques that enable users to model processes that
involve complex chemistry. AspenTech has refined these methods, models and
techniques based on continuing relationships with customers who have performed
millions of simulations using AspenTech software. The Company has expanded its
on-line expertise through its acquisitions of ISI, DMCC, Setpoint, Cambridge
Control and Bechtel PIMS, and the Company believes it is now the technological
leader in the planning and scheduling, IMS, APC and optimization markets.
AspenTech believes that the expertise underlying its software products and
services will assist it in maintaining and enhancing its reputation as a
technological leader across the manufacturing process.


STRATEGY
           AspenTech's strategy is to expand the use of its products and
services to enable customers to improve the design, operation and management of
their manufacturing processes. The key elements of this strategy are:

           Leverage Breadth and Depth of Customer Base. AspenTech considers its
relationships with its existing customers to be an important corporate asset.
AspenTech currently has more than 750 commercial customers worldwide, including
45 of the 50 largest chemical companies in the world and 18 of the 20 largest
petroleum refiners in the world. The Company has historically derived a
significant component of its revenue from additional sales to existing
customers. The Company believes it has a significant opportunity to expand its
existing customer relationships by adding new licensed users, by offering
additional product modules, and by providing consulting and support services.
These solutions are marketed by a single, integrated sales force organized by
customer account. AspenTech is capitalizing on the significant opportunities it
has created to cross-sell modeling products to traditional APC and optimization
customers and vice versa.

           Leverage Lead in the Area of Smart Manufacturing Systems. AspenTech
believes that it has emerged as the leader in the area of integrated design,
control and management applications for process manufacturing ("Smart
Manufacturing Systems"). As the benefits of integrated applications across
process manufacturing design, control and management functions are more widely
understood and appreciated by process manufacturers, AspenTech is expanding its
integration efforts, developing relationships with enterprise resource planning
("ERP") vendors and distributed control system ("DCS") vendors, and offering
customers complete solutions which link the Smart Manufacturing Systems to the
ERP and DCS technology layers.

           Increase Penetration of Process Industries. In recent years,
AspenTech has broadened its penetration of the process industries beyond its
traditional leadership in the chemicals segment to include significant shares of
the petroleum and pulp and paper markets. Many of the same imperatives and
opportunities confront participants in other process industry segments. As the
benefits of its solutions are becoming more widely understood by process
manufacturers, AspenTech is actively pursuing opportunities to expand the use of
its technology in additional vertical markets. For example, AspenTech's
introduction in March 1997 of BatchPlus, a solution for the modeling and
simulation of complex, recipe-based pharmaceutical and batch chemical processes,
has broadened the Company's historically limited presence in these large and
underpenetrated vertical market segments. AspenTech believes the continuous
broadening of its software product and service offerings through acquisition and
internal development will enable AspenTech to expand its reach further. Over
time, AspenTech will also seek to leverage these new customer relationships by
cross-selling its other software product and service offerings.

           Offer Broadest, Integrated Family of Products and Services. AspenTech
offers customers a broad family of software products encompassing the full
manufacturing life-cycle, enabling customers to add compatible software
capabilities as their needs grow. These products can be used as stand-alone
solutions or in concert with other software modules. AspenTech offers process
manufacturers what it believes is the most advanced product functionality
available across a wide range of off-line and on-line applications. The Company
intends to integrate further the APC and optimization tools obtained through its
acquisitions into future generations of its software products. In addition,
AspenTech provides implementation consulting services to ensure that customers
can achieve a successful solution. In certain of AspenTech's projects,
functionality developed in connection with a solution has appeared applicable to
other customers and has been commercialized by AspenTech, such as BatchPlus,
developed in conjunction with Merck & Co.. The Company expects this to continue
to be one of its sources of new products and that its ability to offer its
customers a complete solution will be an increasingly important source of
competitive differentiation. Where acquisition represents the most


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efficient source of product line extension, AspenTech expects to continue to
acquire products and technologies opportunistically, as with its October 1996
purchase of B-JAC International, Inc., a leading supplier of specialized heat
exchanger modeling tools.

           Extend Technology Leadership. AspenTech intends to extend its
reputation as the technology leader and believes its recent acquisitions
represent important opportunities to maintain and enhance its differentiating
capabilities in the marketplace. AspenTech believes its modeling software
solutions include a number of pioneering products and algorithms, and its
on-line offerings are technological leaders in real-time applications,
engineering and consulting solutions for APC and optimization. AspenTech's
reputation for technological leadership continues to be an important source of
attraction for scarce, highly talented engineers and technical personnel.

           Focus on Long-Term Customer Relationships. AspenTech's operating
strategy is driven by a long-term approach to customer relationships. AspenTech
historically derives a substantial portion of its revenues from three- to
five-year software licenses and renewals of those licenses. Because a
significant portion of its revenues come from its installed base, AspenTech
focuses on long-term customer relationships in marketing its process modeling
and plant automation software products and services. Increasingly, cross-selling
opportunities are merging the customer bases of AspenTech's traditional modeling
users with those of the recently acquired companies, who traditionally focused
exclusively on on-line solutions. AspenTech intends to leverage these
relationships to an increasing extent, particularly as the product integrations
are completed. This includes alliances which provide for significant customer
involvement in product development and testing as well as customer sharing of
technology, such as the AspenTech Dow Chemical Co. alliance announced in June
1997.

           Capitalize on Emerging On-Line Market. The Company believes that the
potential market for on-line applications for process industries, while less
mature than the off-line market, may be substantially larger than the potential
off-line market. On-line applications complement existing off-line applications
and afford recurring incremental savings in day-to-day operations. The Company
will seek to continue to develop and expand the market for its IMS, APC and
optimization software and services for the emerging on-line market.

           Partner with Complementary Process Industry Suppliers. In recent
years, shifts toward open technologies, lower-cost and more powerful hardware
platforms, and intensifying global business pressures are causing process
industry customers to look increasingly at purchasing open, best-of-breed
solutions, rather than single-vendor proprietary approaches. In response to this
trend, AspenTech has embarked on a strategy to partner with leading technology
vendors, such as SAP A.G., Yokagawa Electric Corporation, and Elsag Bailey, Inc.
in order to broaden the reach of its marketing organization and to enable its
customers to create integrated solutions that best achieve their goals.


CUSTOMERS
           AspenTech currently has over 750 commercial customers worldwide,
including 45 of the 50 largest chemical companies in the world and 18 of the 20
largest petroleum refiners in the world. The Company derived more than 50% in
fiscal 1995, approximately 45% in fiscal 1996, and more than 50% in fiscal 1997
of revenues from customers outside the United States.


      CHEMICALS
      ---------
      Air Products & Chemicals, Inc.
      BASF AG
      The Dow Chemical Company
      E.I. du Pont de Nemours & Company, Inc.
      Elf Atochem
      Hoechst AG
      Huls AG
      Huntsman Corporation
      Lyondell Petrochemical
      Mitsubishi Chemical Corporation
      Olin Corporation
      Rhone-Poulenc Industrialisation
      Sasol Industries (Pty.) Ltd.
      Shell International Chemie Mij B.V.
      Sumitomo Chemical Co. Ltd.
      Union Carbide Chemicals and Plastics Company, Inc.


      ENGINEERING AND CONSTRUCTION
      ----------------------------
      Bechtel Corporation


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<PAGE>   7
      Fluor Daniel, Inc.
      John Brown Engineers and Constructors B.V.
      Lurgi AG
      The M.W. Kellogg Company
      The Ralph M. Parsons Company
      UOP
      Zimmer AG

      CONSUMER PRODUCTS
      -----------------
      The Procter & Gamble Company
      3M Company
      Unilever Research

      ELECTRIC POWER
      --------------
      ABB Stal AB
      British Nuclear Fuels plc
      Combustion Engineering, Inc.
      GEC Alsthom
      SGN
      Westinghouse Electric Corporation

      FOOD PRODUCTS
      -------------
      Cargill Incorporated
      General Mills, Inc.

      PETROLEUM
      ---------
      Arco Products Company
      British Petroleum
      Chevron Corporation
      Citgo Petroleum Corporation
      Conoco Inc.
      Corpoven, S.A.
      Marathon Oil Company
      Mobil Oil Corporation
      Neste Oy
      Phillips Petroleum Company
      Repsol Petroleo SA
      Shell Oil Company
      Star Enterprise
      Sun Refining and Marketing Company

      PHARMACEUTICALS
      ---------------
      Ciba-Geigy AG
      Eli Lilly and Company
      Fujisawa Pharmaceutical Co., Ltd.
      Genentech, Inc.
      Hoffman-LaRoche, Inc.
      Kyowa-Hakko Kogyo Co., Ltd.
      Merck & Co., Inc.
      Sandoz Technologie AG
      The Upjohn Company

      PULP AND PAPER
      --------------
      Union Camp Corporation
      Weyerhaeuser Company

      METALS AND MINERALS
      -------------------
      Phelps Dodge


           No individual customer represented 10% or more of AspenTech's total
revenues for fiscal 1995, 1996 or 1997. There can be no assurance that any of
the customers listed will continue to license software or purchase services from
AspenTech beyond the term of any existing agreement.



PRODUCTS AND SERVICES

           AspenTech is a leading supplier of software products and services for
the analysis, design and automation of manufacturing facilities by companies in
the process industries. AspenTech's integrated family of software products
enables customers to predict accurately and reliably the performance of a
manufacturing process in order to design, operate and manage manufacturing
processes more efficiently, safely and profitably. These tools are used both
off-line by engineers on desktop computers in connection with the design of new
facilities and processes and the analysis of existing facilities and processes,
and on-line connected directly to plant instrumentation to identify adjustments
that can be made on a real-time basis to optimize performance continually in
response to changing production conditions. In addition, AspenTech can provide
expert consulting, training and support services to augment its software
expertise and offer a complete solution to its customers.

<TABLE>
<CAPTION>
                 -----------------------------  -------------------------------  --------------------
                 Products                       Description                      Category
                 OFF-LINE SOFTWARE
<S>                                             <C>                              <C>

                   ASPEN PLUS(R)                Rigorous steady-state modeling   Modeling
                                                for chemicals, electrolytes,     (steady state
                                                solids, and petroleum assays     processes)

                   SPEEDUP(R)                   Rigorous modeling environment    Modeling
                                                for dynamically simulating       (dynamic processes)
                                                chemical, hydrocarbon, and     
                                                petroleum processes

                   ADVENT(R)                    Simulation tool for designing    Modeling
                                                reduced cost processes for       (process synthesis)
                                                chemical plants and refineries
                                                via process/utility heat
                                                integration

                  BATCH PLUS(TM)                Recipe-based simulation engine   Modeling
                                                that can model one batch or a    (batch process)
                                                whole plant

                 -----------------------------  -------------------------------  --------------------
                 ON-LINE SOFTWARE
                   InfoPlus.21(TM)              A hierarchical, real-time,       IMS
                                                memory-resident configurable
                                                database
</TABLE>


                                       6
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<TABLE>
<S>                                            <C>                              <C>

                   DMCplus(TM)                  Multivariable predictive         APC
                                                constraint process control
                                                application

                   RT-OPT(R)                    Real-time closed-loop            Optimization
                                                optimization product

                 Aspen PIMS(TM)                 Linear programming product to    Planning and
                                                optimize an economic model of    Scheduling
                                                a manufacturing complex          
                 -----------------------------  -------------------------------  --------------------
</TABLE>


OFF-LINE SOFTWARE PRODUCTS
           The Company offers a number of software products for off-line
applications. Off-line software is used primarily to simulate and predict
manufacturing processes in connection with the design of new facilities or
processes and the analysis of existing facilities or processes. ASPEN PLUS is
used to simulate steady state processes in which inputs and conditions are held
constant. ASPEN PLUS can be used in concert with SPEEDUP, dynamic process
modeling software that simulates processes in which inputs and conditions change
over time, such as during plant start-up and shutdown or when feedstocks are
adjusted. ADVENT is process synthesis software that minimizes energy consumption
and emissions from a manufacturing process. BATCH PLUS is modeling and
simulation software for recipe-based pharmaceutical and batch chemical process
manufacturing. Layered on top of these core, integrated off-line applications
are a number of separately sold modules that focus on specialized types of
analysis to model separation systems, batch distillation columns, bioprocess
operations, polymers processes, and other complex systems. All of these products
can operate in Windows. ASPEN PLUS, SPEEDUP, and ADVENT also run on UNIX and
both ASPEN PLUS and SPEEDUP run on DEC VMS. See "Item 1. Product Development" 
and "Item 1a. Risk Factors - Migation to MicroSoft Windows; Emergence of Other 
Standards".

           AspenTech typically licenses its modeling software for a term of
either three or five years. Currently, the annualized cost for a single
U.S.-based user of one of AspenTech's off-line software modules ranges from
$10,000 to $30,000, depending on the product and the license term. The license
fees charged by AspenTech are typically based on the number of licensed users,
with the cost per user declining as the number of licensed seats increases. The
license fee includes a separate maintenance component that covers upgrades,
revisions or enhancements during the term of the license, as well as customer
support.


ON-LINE SOFTWARE PRODUCTS
           For on-line applications, AspenTech offers a family of products and
services that enables customers to better understand and monitor highly complex
manufacturing processes on a real-time basis, and to automate the adjustment of
operating parameters in response to continually changing conditions for improved
process efficiency, safety and cost-effectiveness. AspenTech typically licenses
its on-line software for a term of 99 years. AspenTech's IMS products capture,
display and analyze plant-wide historical and real-time process data, in order
to compare the actual performance to theoretical benchmarks derived from models.
The U.S. list price for an entry-level 99-year IMS license is approximately
$50,000, and varies depending on the number of points of data being collected.
AspenTech's APC and optimization products enable customers to improve the
profitability of a manufacturing facility by determining optimal operating
parameters and simultaneously adjusting multiple process variables to achieve
these targets. The U.S. list price for a 99-year APC or optimization software
license for a single process unit or single facility ranges from $50,000 to
$200,000.


           AspenTech's PIMS products provide economic planning and scheduling
tools to customers which are based on large linear programming models. They
enable customers to make both short-term and strategic decisions which help
identify optimum plant investments. AspenTech typically licenses its PIMS
software for a term of five years or 25 years. The U.S. list price for a license
of AspenTech's PIMS modules range from $10,000 to $200,000 depending on the 
product and the license term. 

           All of these products can operate in Windows. InfoPlus.21, DMCplus,
and RT-OPT also run on DEC VMS, and both InfoPlus.21 and RT-OPT operate on a
UNIX platform. See "Item 1. Product Development" and "Item 1a. Risk Factors -
Migration to Microsoft Windows; Emergence of Other Standards".

CONSULTING SERVICES
           AspenTech can combine its on-line off-the-shelf software products
with design and implementation consulting services in order to market a complete
solution to its customers. The emerging on-line market has fewer commercial
modeling tools than the off-line market. As a result, current on-line
applications typically consist of substantial consulting services combined with
a small component of standard commercial software. These services are
customarily provided pursuant to contracts with engagement terms of
approximately 9 to 24 months. The contracts may be priced on either a
time-and-materials or fixed-price basis. Customers can purchase such services
from other vendors or perform them in-house. The Company believes that, due to
customers' growing awareness of the economic benefits of on-line optimization
and related activities, the demand for services exceeds the number of


                                       7
<PAGE>   9
trained control engineers that can provide these services. AspenTech's IMS, APC
and optimization services business, composed of approximately 330 people, which
AspenTech believes is the largest group of control engineers in the world,
represents a critical resource in its efforts to penetrate the on-line market.
The Company's services personnel are also available to support and maintain its
off-line software products.


MARKETING AND SALES
           AspenTech employs a direct sales force located in key geographic
centers where there are high concentrations of potential business. The Company's
sales approach is designed to provide complete solutions to its customers.
AspenTech's worldwide sales organization is focused by customer account, with an
overall relationship executive responsible for coordinating with regional
account managers and sales engineers. In addition, each sales team includes
participants from the business development group who are responsible for
determining the scope and price of the product or service being offered.
AspenTech believes that its seasoned direct sales force, as well as its ability
to sell at senior levels within customer organizations, are important
competitive distinctions. AspenTech uses sales agents to leverage its direct
sales force and provide local coverage and first-line support in areas of lower
customer concentration. The Company also supplements its direct sales efforts
with a variety of marketing initiatives, including user groups and a triennial
conference, AspenWorld.

           AspenTech devotes substantial resources to increasing the penetration
of its products within existing customers. AspenTech has developed global
technology partnerships with a select group of customers that use modeling
extensively, whereby they meet on a regular basis with AspenTech's senior
technical and managerial staffs to help shape technical direction.

           AspenTech licenses its software products at a substantial discount to
universities that agree to use such products in teaching and research, in order
to stimulate future demand once the students enter the workplace. Currently,
more than 520 universities use its software products in undergraduate
instruction.


COMPETITION
           The Company's software products and services compete with software
tools that are internally developed by companies in the process industries and
with certain modeling, planning and scheduling, IMS, APC and optimization
software products and services that are sold by a number of commercial
suppliers. Increasingly, companies in the process industries are recognizing
that it is inefficient and uneconomical for them to continue to develop and
support this software, and many of them are now deploying commercial software
products alongside their internally developed tools.

           AspenTech's primary commercial competitors in the process modeling
software and services market are Simulation Sciences Inc., Hyprotech, Ltd. (a
subsidiary of AEA Technology plc), and Chemstations, Inc. In the planning and
scheduling market, the Company competes with Bonner and Moore Associates, Inc.
Haverly Systems, Inc. Chesapeake Decision Science, Inc., and Ernst & Young
Wright Killen. In the IMS market, AspenTech primarily competes with Oil Systems
Inc. and Biles and Associates (which entered into an agreement to be acquired by
Simulation Sciences, Inc. in August 1997) and, to a lesser extent, with
distributed control system vendors such as Honeywell Inc. In the APC and
optimization markets, AspenTech competes with the Industrial Automation and
Control business unit of Honeywell Inc., which primarily sells distributed
control system hardware, as well as with Pavilion Technologies, Inc. and the
Simcon division of ABB Asea Brown Boveri (Holding) Ltd. Several smaller
competitors, including Treiber Control, focus exclusively on the APC market.
Emergence of a new competitor or the consolidation of existing competitors could
adversely affect the Company's business, operating results and financial
condition. Certain competitors also supply related hardware products to existing
and potential customers of AspenTech, and may have established relationships
that afford the competitors an advantage in supplying software and services to
those customers.

           AspenTech believes that it competes favorably by offering the
broadest range of integrated off-line and on-line modeling software and
services, and that its size, technology and industry expertise will continue to
provide it with a marketplace advantage over companies that are niche suppliers
focused on a single element of the solution or companies that primarily sell
hardware. The Company's continued success depends on its ability to compete
effectively with its commercial competitors and to persuade prospective
customers to use the Company's products and services instead of, or in addition
to, software developed internally or services provided by their own personnel.
In light of these factors, there is no assurance that the Company will be able
to maintain its competitive position. See "Item 1a. Risk Factors --
Competition."


PRODUCT DEVELOPMENT
           AspenTech's most important product development objective is to build
upon the technical leadership of its software products both individually and as
an integrated solution. Product development activities focus on adding new
chemical engineering analysis and plant operations capabilities, developing new
ease-of-use features and enhancing the user interface, taking advantage of new
hardware capabilities and major new software industry developments, more tightly
integrating AspenTech's family of software products and integrating those
software products with other tools. AspenTech has focused significant efforts on
the development of Windows 95


                                       8
<PAGE>   10
and Windows NT versions of all of its software products and continues to focus
on the continued integration of its family of software products, including
products acquired through past acquisitions.

           AspenTech's approach to Windows is based on a client-server
architecture. AspenTech is developing Windows 95 and Windows NT clients for all
of its core software products not already Windows 95 or Windows NT compatible,
with simulation and database servers running on Windows NT, UNIX and DEC VMS.
The objective of the Windows development is to capitalize on Windows
interoperability and customization capabilities, as well as to provide highly
intuitive graphical user interfaces. A native Windows development environment is
used to ensure full support of all Windows features and object linking and
embedding (OLE) architecture. See "Item 1a. Risk Factors -- Migration to
Microsoft Windows; Emergence of Other Standards."

            AspenTech has integrated overlapping products in each business area
by combining the best components from these products under a Windows graphical
user interface. AspenTech is continuing to work on the development of an open,
distributed object component architecture for all AspenTech products, with the
products sharing common components and allowing incorporation of customer or
third-party components. A central Software Engineering and Architecture
department has facilitated and coordinated component development.


           AspenTech continues to invest in maintaining its technology
leadership through development and enhancement of existing products and
development of new products. The Company has successfully integrated closely
related products such as ASPEN PLUS and SPEEDUP, as well as products from
different divisions such as DMCplus and InfoPlus.21. Release 10 of ASPEN PLUS,
which includes Windows NT capability, is scheduled for release by the end of the
first calendar quarter of 1998 to be followed by Release 11, an
equation-oriented version of ASPEN PLUS, which does not yet have a scheduled
release date. In addition, the Company has completed integration of RT-OPT with
[DMO], AspenTech's dynamic matrix optimization software acquired with the
acquisition DMCC. The Company is also focusing certain resources on the
production of a complete, integrated solution between certain enterprise
resource planning ("ERP") products such as SAP's R/3 and distributed control
systems. Finally, the Company has also established a year 2000 compliance
program to test and, if necessary, modify software to enable it to handle the
date change on and after the year 2000. There can be no assurance that AspenTech
will be successful in enhancing and integrating these software products or that
it will release scheduled releases on time or that a full integrated product
offering will result in the benefits anticipated. See "Item 1a. Risk Factors -
Product Development and Technological Change" and "Migration to Microsoft
Windows; Emergence of Other Standards."


PROPRIETARY RIGHTS
           The Company regards its software as proprietary and relies on a
combination of copyright, patent, trademark and trade secret laws, license and
confidentiality agreements, and software security measures to protect its
proprietary rights. AspenTech has United States patents for the expert guidance
system in its proprietary graphical user interface, simulation and optimization
methods in its optimization software, a process flow diagram generator in its
planning and scheduling software, and a process simulation apparatus in its
polymers software. The Company has registered or applied to register certain of
its significant trademarks in the United States and in certain other countries.

           The Company generally enters into non-disclosure agreements with its
employees and customers, and historically has restricted access to its software
products' source codes, which it regards as proprietary information. In a few
cases, the Company has provided copies of the source code for certain products
to customers solely for the purpose of special customization of the products and
has deposited copies of the source code for certain products in third-party
escrow accounts as security for on-going service and license obligations. In
these cases, the Company relies on nondisclosure and other contractual
provisions to protect its proprietary rights.

           AspenTech distributes its products under non-exclusive and typically
nontransferable license agreements that grant customers the right to use
AspenTech's products, typically for a term of either three or five years in the
case of modeling software products, five and twenty-five years for planning and
scheduling software, or for a term of 99 years in the case of IMS, APC and
optimization software products. The license agreements contain various
provisions that protect AspenTech's ownership of the products and the
confidentiality of the underlying technology.

           The laws of certain countries in which the Company's products are
distributed do not protect the Company's products and intellectual property
rights to the same extent as the laws of the United States. The laws of many
countries in which the Company licenses its products protect trademarks solely
on the basis of registration. The Company currently possesses a limited number
of trademark registrations in certain foreign jurisdictions and does not
possess, and has not applied for, any foreign copyright or patent registrations.
The Company derived more than 50% in fiscal 1995, approximately 45% in fiscal
1996, and more than 50% in fiscal 1997 of its total revenues from customers
outside the United States.

           There can be no assurance that the steps taken by the Company to
protect its proprietary rights will be adequate to deter misappropriation of its
technology or independent development by others of technologies that are
substantially equivalent or superior to the Company's technology. Any such
misappropriation of the Company's technology or development of competitive
technologies could have a material adverse effect on the business, results of
operations and financial condition of the Company. The Company


                                       9
<PAGE>   11
could incur substantial costs in protecting and enforcing its intellectual
property rights. Moreover, from time to time third parties may assert patent,
trademark, copyright and other intellectual property rights to technologies that
are important to the Company. In such an event, the Company may be required to
incur significant costs in litigating a resolution to the asserted claims. There
can be no assurance that such a resolution would not require that the Company
pay damages or obtain a license of a third party's proprietary rights in order
to continue licensing its products as currently offered or, if such a license is
required, that it will be available on terms acceptable to the Company.

           AspenTech believes that, due to the rapid pace of innovation within
the industry, factors such as the technological and creative expertise of its
personnel, the quality of its products, the quality of its technical support and
training courses, and the frequency of software product enhancements are more
important to establishing and maintaining a technology leadership position
within the industry than the various legal protections for its software products
and technology. See "Item 1a. Risk Factors- Dependence on Proprietary
Technology."


EMPLOYEES
           As of June 30, 1997, AspenTech had a total of 1,239 full-time
employees. None of AspenTech's employees is represented by a labor union.
AspenTech has experienced no work stoppages and believes that its employee
relations are good.

           While the Company has substantially expanded the breadth and depth of
its management team in recent years, AspenTech's future success depends to a
significant extent on the continued service of Lawrence B. Evans, the Company's
chief executive officer, its other executive officers and certain technical,
managerial and marketing personnel. The Company believes that its future success
will also depend on its continuing ability to attract and retain highly skilled
technical, managerial and marketing personnel. Competition for such personnel is
intense and there can be no assurance that AspenTech can retain its key
employees or that it can attract, assimilate or retain other highly qualified
technical and commercial personnel in the future. To date, six of the original
eight founders of AspenTech are still employed by AspenTech and are active in
its management. See "Item 1a. Risk Factors - Dependence on Key Personnel".

ITEM 1A. RISK FACTORS 
           Form 10-K contains forward-looking statements within the meaning of
Section 27A of the Securities Act of 1933 and Section 21E of the Securities
Exchange Act of 1934. The Company's actual results could differ materially from
the results contemplated in the forward-looking statements as a result of a
number of factors, including the risk factors set forth below.

           Dependence Upon Increased Market Penetration. Increased use in the
process industries, particularly the chemicals and petroleum industries, of
software and services for the analysis, design and automation of process
manufacturing plants in general and of the Company's software products and
services in particular is critical to the Company's future growth. The Company
believes that a number of factors will determine its ability to achieve
increased market penetration. These factors include product performance,
accuracy of results, ease of implementation and use, breadth and integration of
product offerings, reliability and scope of applications. Failure of the Company
to achieve increased market penetration in the process industries would
substantially restrict the future growth of the Company and could have a
material adverse effect on the Company's business, operating results and
financial condition. See "Item 1. Business -- The AspenTech Advantage" and "--
Strategy."

           Fluctuations in Quarterly Operating Results. The Company's operating
results have fluctuated in the past and may fluctuate significantly in the
future as a result of a variety of factors, including purchasing patterns,
timing of new products and enhancements by the Company and its competitors, and
fluctuating foreign economic conditions. In addition, the Company ships software
products within a short period after receipt of an order and typically does not
have a material backlog of unfilled orders of software products. Therefore,
revenues from software licenses in any quarter are substantially dependent on
orders booked in that quarter. Historically, a majority of each quarter's
revenues from software licenses has come from license contracts that have been
effected in the final weeks of that quarter. The revenues for a quarter
typically include a number of large orders. If the timing of any of these orders
is delayed, it could result in a substantial reduction in revenues for that
quarter. Since the Company's expense levels are based in part on its
expectations as to future revenues, the Company may be unable to adjust spending
in a timely manner to compensate for any revenue shortfall and any revenue
shortfalls would likely have a disproportionate adverse effect on net income.
Prior to fiscal 1996, the Company experienced a net loss for the first quarter
of each fiscal year, in part because a substantial portion of the Company's
revenues is derived from countries other than the United States where business
is slow during the summer months and also in part because of the timing of
renewals of software licenses. The Company expects that these factors will
continue to affect its operating results and that the Company may experience net
losses in the initial quarter of future fiscal years. See "Item 7. Management's
Discussion and Analysis of Financial Condition and Results of Operations --
Quarterly Results."


                                       10
<PAGE>   12
           Concentration of Revenues in the Chemicals and Petroleum Industries.
The Company derives a significant portion of its revenues from companies in the
chemicals and petroleum industries. Accordingly, the Company's future success is
dependent upon the continued demand for modeling software by companies in the
chemicals industry and for planning and scheduling, IMS, APC and optimization
software and services by companies in the chemical and petroleum industries. The
chemical and petroleum industries are highly cyclical. The Company believes that
economic downturns in the United States, Europe, Japan, Asia and South America
and pricing pressures experienced by chemical and petroleum companies in
connection with cost-containment measures have led to delays and reductions in
certain capital and operating expenditures by many of such companies worldwide.
The Company's revenues have in the past been, and may in the future be, subject
to substantial period-to-period fluctuations as a consequence of such industry
patterns, as well as general domestic and foreign economic conditions and other
factors affecting spending by companies in the Company's target process
industries. There can be no assurance that such factors will not have a material
adverse effect on the Company's business, operating results and financial
condition. See "Item 7. Management's Discussion and Analysis of Financial
Condition and Results of Operations -- Results of Operations."

           Product Development and Technological Change. The market for software
and services for the analysis, design and automation of process manufacturing
plants is characterized by continual change and improvement in computer hardware
and software technology. The Company's future success will depend on its ability
to enhance its current software products and services, to introduce new software
products and services that keep pace with technological developments, and to
continue to address the changing needs of its customers. There can be no
assurance that the Company will be successful in developing and marketing new
and enhanced products and services, or that its products and services will
continue to address adequately the needs of the marketplace. Like many other
software products, the Company's products have on occasion contained undetected
errors or "bugs." In addition, because new releases of the Company's products
are initially installed only by a small number of customers, any errors or
"bugs" in those new releases may not be detected for a number of months after
the delivery of the software. If the Company's products do not perform
substantially as expected or are not accepted in the marketplace, the Company's
business, operating results and financial condition would be materially
adversely affected. See "Item 1. Business -- Product Development."

           Dependence on Key Personnel. The Company's future success depends to
a significant extent on Lawrence B. Evans, the Company's chief executive
officer, its other executive officers, and certain key technical, managerial and
marketing personnel. The loss of the services of any of these individuals or
groups of individuals could have a material adverse effect on the Company's
business, operating results and financial condition. None of the Company's
executive officers has entered into an employment agreement with the Company,
and the Company does not have, and is not contemplating securing, any
significant amount of key-man life insurance on any of its executive officers or
other key employees. The Company believes that its future success also will
depend significantly upon its ability to attract, motivate and retain additional
highly skilled technical, managerial and marketing personnel. Competition for
such personnel is intense, and there can be no assurance that the Company will
be successful in attracting and retaining the personnel it requires to continue
to grow and operate profitably. See "Item 1. Business -- Employees."

           Product Liability. The sale and implementation of on-line
applications by the Company may entail the risk of product liability claims. The
Company's APC and optimization software products and services are used in the
design, operation and management of manufacturing processes at large facilities,
and any failure by the software at those facilities could result in significant
claims for damages or for violations of environmental, safety and other laws and
regulations. The Company's agreements with its customers generally contain
provisions designed to limit the Company's exposure to potential product
liability claims. It is possible, however, that the limitation of liability
provisions contained in the Company's license agreements may not be effective as
a result of federal, state or local laws or ordinances or unfavorable judicial
decisions. A successful product liability claim against the Company could have a
material adverse effect upon the Company's business, operating results and
financial condition.

           Migration to Microsoft Windows; Emergence of Other Standards.
AspenTech believes that operating systems such as to Microsoft Windows, due to
their interoperability and customization capabilities, are increasingly the
preferred choice of certain of its customers. AspenTech has developed Windows 95
versions of its software products and Windows NT versions of most of its core
products. It has developed a Windows NT version of ASPEN PLUS which is in test
stages and is developing a Windows NT version of RT-OPT. There can be no
assurance of customer acceptance of Windows versions of all products, or that
they will be competitive with offerings form the Company's competition. Although
the Company does not believe that there are currently other operating platforms
which are in demand by customers, there can be no assurance that customers will
not migrate to or require compatibility with other systems such as Java(TM). The
Company is also aware of customer concerns that its products be able to handle
the date change on and after the year 2000 and has established a compliance
program to test and, if necessary, modify new versions of its products. Any such
failure or delay in developing and releasing new operating systems versions or
testing and/or modifying its software to be year 2000 compliant could affect the
Company's competitive position or lead to product obsolescence in the future.
See "Item 1. Business -- Product Development" and "-- Competition."

           Dependence on Proprietary Technology. The Company regards its
software as proprietary and relies on a combination of copyright, patent,
trademark and trade secret laws, license and confidentiality agreements, and
software security measures to protect its proprietary rights. AspenTech has
United States patents for the expert guidance system in its proprietary
graphical user interface, simulation and optimization methods in its
optimization software, a process flow diagram generator in its planning and
scheduling


                                       11
<PAGE>   13
software, and a process simulation apparatus in its polymers software. The
Company has registered or applied to register certain of its significant
trademarks in the United States and certain other countries. The Company
generally enters into non-disclosure agreements with its employees and
customers, and historically has restricted access to its software products'
source codes, which it regards as proprietary information. In a few cases, the
Company has provided copies of the source code for certain products to customers
solely for the purpose of special customization of the products and has
deposited copies of the source code for certain products in third-party escrow
accounts as security for on-going service and license obligations. In these
cases, the Company relies on nondisclosure and other contractual provisions to
protect its proprietary rights.

           The laws of certain countries in which the Company's products are
distributed do not protect the Company's products and intellectual property
rights to the same extent as the laws of the United States. The laws of many
countries in which the Company licenses its products protect trademarks solely
on the basis of registration. The Company currently possesses a limited number
of trademark registrations in certain foreign jurisdictions and does not possess
any foreign copyright or patent registrations. The Company derived more than 50%
in fiscal 1995, approximately 45% in fiscal 1996, and more than 50% in fiscal
1997 of its revenues from customers outside the United States.

           There can be no assurance that the steps taken by the Company to
protect its proprietary rights will be adequate to deter misappropriation of its
technology or independent development by others of technologies that are
substantially equivalent or superior to the Company's technology. Any such
misappropriation of the Company's technology or development of competitive
technologies could have a material adverse effect on the business, results of
operations and financial condition of the Company. The Company could incur
substantial costs in protecting and enforcing its intellectual property rights.
Moreover, from time to time third parties may assert patent, trademark,
copyright and other intellectual property rights to technologies that are
important to the Company. In such an event, the Company may be required to incur
significant costs in litigating a resolution to the asserted claims. There can
be no assurance that such a resolution would not require that the Company pay
damages or obtain a license of a third party's proprietary rights in order to
continue licensing its products as currently offered or, if such a license is
required, that it will be available on terms acceptable to the Company. See
"Item 1. Business -- Proprietary Rights."

           Competition. The Company's software products compete with software
tools that are internally developed by companies in the process industries and
with certain process modeling, planning and scheduling, IMS, APC and
optimization software products that are sold by a number of commercial
suppliers. AspenTech's primary commercial competitors in the process modeling
software market are Simulation Sciences, Inc., Hyprotech, Ltd. (a subsidiary of
AEA Technology plc) and Chemstations, Inc. In the planning and scheduling
market, the Company competes with Bonner and Moore Associates, Inc., Haverly
Systems, Inc., Chesapeake Decision Science, Inc., and Ernst & Young Wright
Killen. In the IMS market, AspenTech primarily competes with Oil Systems Inc.
and Biles and Associates (which entered into an agreement  to be acquired by
Simulation Sciences, Inc. in August 1997.) and, to a lesser extent, with
distributed control system vendors such as Honeywell Inc. In the APC and
optimization markets, AspenTech competes with the Industrial Automation and
Control business unit of Honeywell Inc., which primarily sell distributed
control system hardware, as well as with Pavilion Technologies, Inc. and the
Simcon division of ABB Asea Brown Boveri (Holding) Ltd. Several smaller
competitors, including Treiber Control, focus exclusively on the APC market.
There has also been a number of acquisitions and consolidations which expand the
breadth of product and service offerings by certain of these competitors
including the acquisition of both Interplant Consulting, Inc., a provider of
real-time database applications, and Measurex Corporation, a provider of control
systems in the pulp and paper industry, by Honeywell, Inc.; Hyprotech, Ltd. by
AEA Technologies plc; and Visual Solutions, Inc., a provider of simulation
software and services, the on-line technology division of Raytheon Engineers
Contractors, Inc. and Biles & Associates, a provider of information management
and control solutions, by Simulation Sciences, Inc. Emergence of a new
competitor or the consolidation of existing competitors could adversely affect
the Company's business, operating results and financial condition. Certain
competitors also supply related hardware products to existing and potential
customers of AspenTech, and may have established relationships that afford the
competitors an advantage in supplying software and services to those customers.
The Company's continued success depends on its ability to compete effectively
with its commercial competitors and to persuade prospective customers to use the
Company's products and services instead of, or in addition to, software
developed internally or services provided by their own personnel. In light of
these factors, there is no assurance that the Company will be able to maintain
its competitive position. See "Item 1. Business -- Competition."

           Management of Growth. Since fiscal 1990, the Company has experienced
substantial growth in the number of its employees, the scope of its operating
and financial systems, and the geographic area of its operations. The Company's
operations have expanded significantly through both internally generated growth
and acquisitions, particularly the acquisitions of DMCC and Setpoint in the
third quarter of fiscal 1996. This growth has resulted in an increase in the
level of responsibility for management personnel. To manage its growth
effectively, the Company must continue to implement and improve its operating
and financial systems, and to retain and increase its employee base. There can
be no assurance that the management systems currently in place will be adequate
or that the Company will be able to manage the Company's recent or future growth
successfully, and any failure to do so could have material adverse effect on the
Company's business, operating results and financial condition. See "Item 7.
Management's Discussion and Analysis of Financial Condition and Results of
Operations -- Results of Operations."


                                       12
<PAGE>   14
           International Operations. The Company derived more than 50% in fiscal
1995, approximately 45% in fiscal 1996, and more than 50% in fiscal 1997 of its
revenues from customers outside the United States. The Company anticipates that
revenues from customers outside the United States will continue to account for a
significant portion of its total revenues in the foreseeable future. The
Company's operations outside the United States are subject to certain risks,
including unexpected changes in regulatory requirements, exchange rates, tariffs
and other barriers, political and economic instability, difficulties in managing
distributors or representatives, difficulties in staffing and managing foreign
subsidiary operations, difficulties or delays in translating products and
product documentation into foreign languages, and potentially adverse tax
consequences. There can be no assurance that any of these factors will not have
a material adverse effect on the Company's business, operating results and
financial condition.

           The impact of future exchange rate fluctuations on the Company's
financial condition and results of operations cannot be accurately predicted. In
recent years, the Company has increased the extent to which it denominates
arrangements with customers outside the United States in the currencies of the
country in which the software or services are provided. From time to time the
Company has engaged in, and may continue to engage in, hedges of a significant
portion of installment contracts denominated in foreign currencies. There can be
no assurance that any hedging policies implemented by the Company will be
successful or that the cost of such hedging techniques will not have a
significant impact on the Company's business, results of operations or financial
condition. See "Item 7. Management's Discussion and Analysis of Financial
Condition and Results of Operations."

           Risks Associated With Future Acquisitions. To expand its markets, the
Company's business strategy includes growth through additional acquisitions.
Identifying and pursuing acquisition opportunities and integrating acquired
products and businesses requires a significant amount of management time and
skill. There can be no assurance that the Company will be able to identify
suitable acquisition candidates, consummate any acquisition on acceptable terms
or successfully integrate any acquired business into the Company's operations.
There also can be no assurance that any future acquisition will not have an
adverse effect upon the Company's operating results, particularly in the fiscal
quarters immediately following consummation of the acquisition while the
acquired business is being integrated into the Company's operations. As a result
of acquisitions, the Company may encounter unexpected liabilities and
contingencies associated with the acquired businesses. The Company may use
Common Stock or Preferred Stock or may incur additional long-term indebtedness
or a combination thereof for all or a portion of the consideration to be paid in
future acquisitions. The issuance of Common Stock or Preferred Stock in
acquisitions could result in dilution to existing stockholders, while the use of
cash reserves or significant debt financing to fund acquisitions could reduce
the Company's liquidity.

           Potential Volatility of Stock Price. The stock market has from time
to time experienced extreme price and volume fluctuations, particularly in the
high technology sector, and those fluctuations have often been unrelated to the
operating performance of particular companies. In addition, factors such as
announcements of technological innovations or new products by the Company or its
competitors, as well as market conditions in the computer software or hardware
industries, may have a significant impact on the market price of the Company's
Common Stock.

           Effect of Certain Charter and By-Law Provisions and Anti-Takeover
Provisions; Possible Issuances of Preferred Stock. The Company's Restated
Articles of Organization, its by-laws and certain Massachusetts laws contain
provisions that may discourage acquisition bids for the Company and that may
reduce the temporary fluctuations in the trading price of the Company's Common
Stock which are caused by accumulations of stock, thereby depriving stockholders
of certain opportunities to sell their stock at temporarily higher prices or
receive a premium for their shares as part of an acquisition of the Company.
Preferred Stock may be issued by the Company in the future without stockholder
approval and upon such terms as the Board of Directors may determine. The rights
of the holders of Common Stock will be subject to, and may be adversely affected
by, the rights of the holders of any Preferred Stock that may be issued in the
future. The issuance of Preferred Stock, while providing desirable flexibility
in connection with possible acquisitions and other corporate purposes, could
have the effect of making it more difficult for a third party to acquire, or of
discouraging a third party from acquiring, a majority of the outstanding stock
of the Company. The Company has no present plans to issue any shares of
Preferred Stock.


ITEM 2.  PROPERTIES
           AspenTech's principal offices occupy the entire building 
(approximately 110,000 square feet) of office space in Cambridge, Massachusetts,
where its principal offices are located. AspenTech's lease of the premises of
its principal offices expires on September 30, 2002. In addition, AspenTech and
its subsidiaries lease office space in Midlothian, Virginia, Brecksville and
Cincinnati, Ohio; Houston, Texas; Bothell, Washington; Brussels, Belgium;
Calgary, Alberta, Canada; Cambridge and Warrington, England; Hong Kong; Tokyo,
Japan; Best, The Netherlands; Singapore; and other locations of its sales and
customer support offices. AspenTech believes that its existing facilities are
adequate for its needs currently and for the reasonably foreseeable future and
that, if additional space is needed, such space will be available on acceptable
terms.


ITEM 3.  LEGAL PROCEEDINGS
           AspenTech is not a party to any material litigation.


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<PAGE>   15
ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

         No matter was submitted to a vote of security holders during the fourth
quarter of the fiscal year covered by this report.


ITEM 4A. EXECUTIVE OFFICERS OF THE REGISTRANT

         The executive officers and directors of the Company, and their ages as
of September 26, 1997, are as follows:


<TABLE>
<CAPTION>
                NAME                    AGE                  POSITION
       ---------------------------      ---      --------------------------------------
<S>                                     <C>      <C>                                  
       Lawrence B. Evans.....            62      Chairman of the Board of Directors
                                                 and
                                                 Chief Executive Officer
       Joseph F. Boston......            60      President and Director
       Gresham T. Brebach, Jr. (2)       56      Director
       Douglas R. Brown(2)               43      Director
       Joan C. McArdle(1)(2)             45      Director
       Alison Ross(1)........            37      Director
       David L. McQuillin                40      Executive Vice President,
                                                 Worldwide Sales & Marketing
       Mary A. Palermo.......            40      Executive Vice President, Finance
                                                 and
                                                 Chief Financial Officer
       Joel B. Rosen.........            39      Executive Vice President
       John Ayala                        42      Senior Vice President
       Herbert I. Britt......            52      Senior Vice President,
                                                 and
                                                 Chief Technical Officer
       Michael Catt..........            45      Senior Vice President
       John Derbyshire.......            46      Senior Vice President
       Vladimir Mahalec......            50      Senior Vice President
       David Mushin..........            41      Senior Vice President
       Stephen J. Doyle......            44      Vice President, General Counsel
                                                 and
                                                 Chief Legal Officer
       Lisa Zappala..........            37      Treasurer
</TABLE>

- ----------

(1)  Member of Audit Committee of the Board of Directors
(2)  Member of Compensation Committee of the Board of Directors

         Lawrence B. Evans, the principal founder of the Company, has served as
Chairman of the Board of Directors and Chief Executive Officer of the Company
since 1984. He also served as Treasurer of the Company from 1984 through
February 1995 and as President from the inception of the Company until 1984. Mr.
Evans was a Professor of Chemical Engineering at Massachusetts Institute of
Technology ("M.I.T.") from 1962 to 1990 and was the principal investigator for
the Advanced System for Process Engineering ("ASPEN") Project at M.I.T., which
extended from 1976 to 1981. Mr. Evans holds a B.S. in Chemical Engineering from
the University of Oklahoma, and an M.S.E. and Ph.D. in Chemical Engineering from
the University of Michigan.

         Joseph F. Boston, a founder of the Company, has served as President of
the Company since 1984 and as a director since 1981. Mr. Boston served as both
the Principal Engineer and as an Associate Project Manager from 1977 to 1981 of
the ASPEN Project at M.I.T. Mr. Boston holds a B.S. in Chemical Engineering from
Washington University, and a Ph.D. in Chemical Engineering from Tulane
University.

         Gresham T. Brebach, Jr. has served as a director of the Company since
August 1995. Since February 1997, Mr. Brebach has been President and Chief
Executive Office of Nextera Enterprises, L.L.C., a Lexington, Massachusetts
based consulting company. Between January 1995 and February 1997, Mr. Brebach
was Executive Vice President -- Client Services of Renaissance Solutions, 


                                       14
<PAGE>   16
Inc., a provider of management consulting and client/server systems integration
services. From August 1994 to December 1994, Mr. Brebach operated his own
consulting firm, Brebach and Associates. From April 1993 to August 1994, Mr.
Brebach served as Executive Vice President of Digital Consulting, the management
consulting division of Digital Equipment Corporation. From December 1989 to
April 1993, Mr. Brebach was a Director in the Consumer and Industrial Products
sector of McKinsey & Company, a management consulting firm.

         Douglas R. Brown has served as a director of the Company since 1986.
Mr. Brown was appointed the President, Chief Executive Officer and Director of
Advent International Corporation, a venture capital investment firm, in January
1996. Mr. Brown previously served as Chief Investment Officer of Advent
International Corporation since 1994, as well as Senior Vice President and
Managing Director -- Europe since 1990. Mr. Brown holds a B.S. in Chemical
Engineering from M.I.T. and an M.B.A. from the Harvard Graduate School of
Business Administration.

         Joan C. McArdle has served as a director of the Company since July
1994. Since 1985 she has been a Vice President of MCRC, a Boston-based
investment company that was a creditor and warrant holder of the Company. See
"Item 7. Management's Discussion and Analysis of Financial Condition and Results
of Operations -- Liquidity and Capital Resources." Ms. McArdle holds an A.B. in
English from Smith College.

         Alison Ross has been a director of the Company since February 1996. Ms.
Ross is the President of Smart Finance & Co., an investment banking consulting
firm she founded in January 1995. As described below, Smart Finance & Co.
provides advisory services to the Company from time to time. From September 1992
to January 1995, Ms. Ross was a Principal of Montgomery Securities. From
September 1991 through August 1992, Ms. Ross served as Special Assistant to the
Secretary of the Cabinet in the Executive Office of the President of the United
States, as part of a one-year appointment as a White House Fellow. From 1986 to
August 1991, she was a Vice President of Goldman, Sachs & Co. Ms. Ross holds an
S.B. in Economics and an S.M. in Management from M.I.T.

         David L. McQuillin has served as Executive Vice President, Worldwide
Sales & Marketing since June 1997. Prior to joining the Company, Mr. McQuillin
held several positions at Honeywell, Inc. Mr. McQuillin holds a B.S., in Applied
Science from Miami University.

         Mary A. Palermo has served as Chief Financial Officer since May 1989.
She joined the Company in November 1987 as Director of Finance, and was promoted
to Vice President in May 1989, to Senior Vice President, Finance in June 1993
and to Executive Vice President, Finance in December 1995. From 1979 to 1982,
Ms. Palermo held several positions at Arthur Andersen LLP. Ms. Palermo holds a
B.S. in Accounting from Boston College and is a C.P.A.

         Joel B. Rosen has served as Executive Vice President, since December
1995. He joined the Company as Director of Marketing in August 1988, and was
promoted to Vice President, Marketing in April 1991, to Senior Vice President,
Marketing in June 1993 and to Senior Vice President, Marketing and New
Businesses in July 1994. From 1984 to 1988, Mr. Rosen held several positions at
Bain & Company. Mr. Rosen holds an A.B. in Economics from Harvard College and an
M.B.A. from the Harvard Graduate School of Business Administration.

         John S. Ayala has served as Senior Vice President of the Company and
President, Advanced Control and Optimization Division since May 1997. Prior to
its merger with AspenTech in 1996, he served as Vice President, Optimization of
Dynamic Matrix Control Corporation. From 1987 to 1996, he served as Senior Vice
President of Optimization. Mr. Ayala holds B.S. and M.S. degrees in Chemical
Engineering from M.I.T.


         Herbert I. Britt, a founder of the Company, has served as Senior Vice
President, Corporate Product Planning and Development since January 1996 and
Chief Technical Officer since April 1997. Since the Company's inception Mr.
Britt has led its product development efforts in various capacities. From 1981
to March 1991, he served as Vice President, Product Development, and from April
1991 to January 1996, he served as Senior Vice President, Product Management.
From 1977 to 1981, he was an Associate Project Manager for the ASPEN Project at
M.I.T. Mr. Britt holds a B.S. and Ph.D. in Chemical Engineering from the
University of Missouri.


         Michael L. Catt has served as Senior Vice President, Production
Management Division since 1996. Prior to its merger with AspenTech, 1996, he
served as Vice President, Sales and Marketing of Setpoint, Inc. Mr. Catt holds a
B.S. in Chemical Engineering from Perdue University.

         John Derbyshire has served as Senior Vice President, since January
1996. Prior to its merger with AspenTech, he served as Vice President and
General Manager of Software Products Division of Setpoint, Inc. Mr. Derbyshire
holds a B.S. in Chemical Engineering from University of Salford, United Kingdom.

         Vladimir Mahalec has served as Senior Vice President, since January
1996. He joined the Company in October 1991 as Vice President and was promoted
to Vice President and General Manager of Optimization in 1994. Mr. Mahalec has
his dipl.Ing from the University of Zagreb Croatia and obtained a Ph.D. from the
University of Houston under a Fullbright Scholarship program.


                                       15
<PAGE>   17
         David Mushin has served as Senior Vice President and General Manager,
Information Management Division since January 1996. From 1991 to 1996, Mr.
Mushin served as Vice President and General Manager of Plant Operations. Prior
to its merger with AspenTech in 1991, he served as General Manager of Prosys
Technology. Mr. Mushin holds a Masters in Chemical Engineering from the
University of Cambridge, England.


         Stephen J. Doyle has served as Vice President, General Counsel and
Chief Legal Officer since September 1996. Prior to joining the Company, Mr.
Doyle was a partner in Mirick, O'Connell, DeMallie & Lougee concentrating in
technology and international business law from 1994 to 1996. From 1986 to 1994,
Mr. Doyle was International Counsel to Prime Computer (renamed Computervision
Corporation) and from 1981 to 1985 was International Attorney for the Bank of
Boston. From 1978 to 1981, Mr. Doyle was an attorney in private practice. Mr.
Doyle holds a B.A. from Georgetown University and J.D. and M.B.A. degrees from
the University of Denver.


         Lisa Zappala has served as Treasurer since 1985. She joined the company
in January 1993 as Director of Financial Operations and was promoted to
Treasurer in 1985. From 1981 to 1993, Ms. Zappala held several positions at
Arthur Andersen LLP. Ms. Zappala holds a B.S. in Accounting from Boston College
and is a C.P.A.



         The Company's Board of Directors is divided into three classes, with
one class of directors elected each year at the annual meeting of stockholders
for a three-year term of office. All directors of one class hold their positions
until the annual meeting of stockholders at which the terms of the directors in
such class expire and until their respective successors are elected and
qualified. Mr. Evans and Ms. McArdle serve in the class whose terms expire in
1997; and Mr. Boston and Mr. Brebach serve in the class whose terms expire in
1998. Mr. Brown and Ms. Ross serve in the class whose terms expires in 1999.
Executive officers of the Company are elected annually by the Board of Directors
and serve at the discretion of the Board of Directors or until their successors
are duly elected and qualified.

         The Company's future success depends to a significant extent on
Lawrence B. Evans, the Company's chief executive officer, its other executive
officers and certain technical, managerial and marketing personnel. The loss of
the services of any of these individuals or group of individuals could have a
material adverse effect on the Company's business, operating results and
financial condition. See "Item 1a. Risk Factors - Dependence on Key Personnel."

         Directors who are not full-time employees of the Company receive an
annual fee of $15,000 for their services, plus $1,500 for each regularly
scheduled meeting attended. Directors also participate in the 1995 Directors
Stock Option Plan.

         The Company has adopted its 1995 Employees Stock Purchase Plan (the
"Stock Purchase Plan"), its 1995 Stock Option Plan (the "1995 Plan"), 1995
Directors Stock Option Plan (the "1995 Directors Plan") and 1996 Special Stock
Option Plan ("1996 Special Plan") which provided for the issuance of incentive
stock options and non-qualified options and its 401(k) Plan (the "401(k) Plan").
See Notes 9(c), (d) and (e) and Note 14 of Notes to Consolidated Financial
Statements.

         The Board of Directors has appointed an Audit Committee and a
Compensation Committee. The Audit Committee reviews the scope and results of the
annual audit of the Company's consolidated financial statements conducted by the
Company's independent accountants, the scope of other services provided by the
Company's independent accountants, proposed changes in the Company's financial
and accounting standards and principles, and the Company's policies and
procedures with respect to its internal accounting, auditing and financial
controls. The Audit Committee also makes recommendations to the Board of
Directors on the engagement of the independent accountants, as well as other
matters which may come before it or as directed by the Board of Directors. The
Compensation Committee administers the Company's compensation programs,
including the Stock Purchase Plan, the 1995 Plan, the 1995 Directors Plan, the
1996 Special Plan and the 401(k) Plan, and performs such other duties as may
from time to time be determined by the Board of Directors.


                                       16
<PAGE>   18

                                     PART II

ITEM 5.  MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER MATTERS


PRICE RANGE OF COMMON STOCK

Since October 26, 1994, the Company's Common Stock has traded on the Nasdaq
National Market under the symbol "AZPN." The following table sets forth, for the
periods indicated, the high and low sale prices per share of the Common Stock as
reported on the Nasdaq National Market.



<TABLE>
<CAPTION>
FISCAL 1996              HIGH            LOW
- -----------              ----            ---
<S>                     <C>            <C>   
First Quarter ........  $15.00         $11.75
Second Quarter .......   18.50          12.375
Third Quarter ........   21.50          15.75
Fourth  Quarter ......   28.625         21.125
</TABLE>


<TABLE>
<CAPTION>
                         HIGH            LOW
                         ----            ---
FISCAL 1997
- -----------
<S>                    <C>             <C>   
First Quarter .......   $36.375        $20.00
Second Quarter ......    42.50          29.625
Third Quarter .......    41.00          25.75
Fourth Quarter ......    39.625         24.75
</TABLE>

         As of June 30, 1997, there were 826 holders of record of the Common
Stock. The Company has never declared or paid cash dividends on its capital
stock.

         The Company currently intends to retain all of its earnings, if any,
for use in its business and does not anticipate paying any cash dividends in the
foreseeable future. In addition, under the terms of the Company's bank line of
credit, the Company is prohibited from paying any cash dividends. Any future
determination relating to dividend policy will be made at the discretion of the
Board of Directors of the Company and will depend on a number of factors,
including the future earnings, capital requirements, financial condition and
future prospects of the Company and such other factors as the Board of Directors
may deem relevant.



ITEM 6.  SELECTED FINANCIAL DATA

         The selected consolidated balance sheet data as of June 30, 1996 and
1997 and the selected consolidated statement of income data for each of the
years ended June 30, 1995, 1996 and 1997 have been derived from the Company's
Consolidated Financial Statements, which have been audited by Arthur Andersen
LLP, independent public accountants, included elsewhere in this Form 10-K. The
selected consolidated balance sheet data as of June 30, 1993, 1994 and 1995 and
the selected consolidated statement of income data for the year ended June 30,
1993 have been derived from the Company's Consolidated Financial Statements,
which also have been audited by Arthur Andersen LLP, not included in this Form
10-K. The following selected consolidated financial data are qualified by
reference to the more detailed Consolidated Financial Statements of the Company
and Notes thereto included elsewhere in this Form 10-K, and should be read in
conjunction with such Consolidated Financial Statements and Notes and the
discussion under "Item 7. Management's Discussion and Analysis of Financial
Condition and Results of Operations."


                                       17
<PAGE>   19
<TABLE>
<CAPTION>
                                                                                    YEAR ENDED JUNE 30,
                                                        ---------------------------------------------------------------------------
                                                          1993            1994            1995             1996              1997
                                                        --------        --------        ---------        ---------        ---------
                                                                         (In thousands, except per share data)
<S>                                                     <C>             <C>             <C>              <C>              <C>      
STATEMENT OF INCOME DATA:
   Revenues .....................................       $ 33,867        $ 44,975        $  57,498        $ 103,609        $ 180,299
                                                        --------        --------        ---------        ---------        ---------

   Cost of revenues .............................          8,918           9,641           10,257           26,425           53,240
   Selling and marketing ........................         11,744          18,095           23,233           34,691           53,517
   Research and development .....................          7,268           8,159           11,375           20,208           31,153
   General and administrative ...................          4,529           4,460            5,132            9,565           15,933
   Charge for in-process research and development             --              --               --           24,421            8,664
   Costs related to acquisition .................             --              --              950               --               --
                                                        --------        --------        ---------        ---------        ---------

                                                          32,459          40,355           50,947          115,310          162,507
                                                        --------        --------        ---------        ---------        ---------
      Income (loss) from operations .............          1,408           4,620            6,551          (11,701)          17,792

   Foreign currency exchange gain (loss ) .......             47             (56)              34             (223)            (236)
   Income (loss) on equity in joint ventures ....             --             (39)              22               10               26
   Interest income ..............................          2,012           1,789            3,095            3,666            5,323
   Interest expense .............................           (532)           (529)            (561)          (1,323)            (151)
                                                        --------        --------        ---------        ---------        ---------

      Income (loss) from continuing operations
        before provision for income taxes .......          2,935           5,785            9,141           (9,571)          22,754

   Provision for income taxes ...................          1,081           2,087            3,725            5,614            9,599
                                                        --------        --------        ---------        ---------        ---------
   Income (loss) from continuing operations .....          1,854           3,698            5,416          (15,185)          13,155

   Discontinued operations:
      Income (loss) from operations .............            (40)             --               --               --               --
      Loss on disposal ..........................           (532)             --               --               --               --
                                                        --------        --------        ---------        ---------        ---------
   Net income (loss) ............................       $  1,282        $  3,698        $   5,416        $ (15,185)       $  13,155
                                                        ========        ========        =========        =========        =========

   Net income (loss) per common and
      common equivalent share (1)(2):
   Continuing operations ........................       $   0.14        $   0.28        $    0.35        $   (0.96)       $    0.63

                                                        ========        ========        =========        =========        =========
   Net income (loss) ............................       $   0.10        $   0.28        $    0.35        $   (0.96)       $    0.63
                                                        ========        ========        =========        =========        =========

   Weighted average number of common and
     common equivalent shares outstanding(1) ....         12,938          13,090           15,562           15,857           20,967
                                                        ========        ========        =========        =========        =========
</TABLE>


<TABLE>
<CAPTION>
                                                                         YEAR ENDED JUNE 30,
                                                    -----------------------------------------------------------------
                                                     1993          1994          1995           1996           1997
                                                    -------       -------       -------       --------       --------
                                                                            (In thousands)
<S>                                                 <C>           <C>           <C>           <C>            <C>     
BALANCE SHEET DATA:
Working capital .............................       $ 6,123       $ 7,774       $27,594       $ 68,917       $ 71,011
Total assets ................................        32,764        42,009        75,697        160,167        192,264
Long-term debt and capital lease obligations,
  less current portion ......................         2,251         2,576         4,087            706            462
Total stockholders' equity ..................        13,402        17,156        41,789         99,835        131,441
</TABLE>


- --------------------------
(1)      Computed as described in Note 2(i) of Notes to Consolidated Financial
         Statements.
(2)      The Company has never declared or paid cash dividends on its capital
         stock.


                                       18
<PAGE>   20
ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS

         Since its founding in 1981, the Company has developed and marketed
software and services to the process industries. The Company's revenues have
grown each year since 1983, when the Company introduced the commercial version
of its ASPEN PLUS modeling software product. In addition to internally generated
growth, the Company has completed a number of acquisitions during the past three
fiscal years. In the fourth quarter of fiscal 1995, AspenTech acquired ISI, a
leading supplier of IMS software. In the third quarter of fiscal 1996, the
Company acquired DMCC and Setpoint, gaining additional expertise in IMS, APC,
and optimization software and services. In the second quarter of fiscal 1997,
AspenTech acquired four additional companies, B-Jac International, the process
control division of Cambridge Control Limited, the planning and scheduling
software division of Bechtel Corporation and Basil Joffe Associates, Inc.
gaining additional modeling, APC, planning, and scheduling expertise. The ISI
and B-Jac International acquisitions were accounted for as pooling of interest
transactions. The Company's financial statements, due to the immateriality of
the B-Jac acquisition, have been restated for ISI only. The remaining
acquisitions were accounted for as purchase transactions; therefore, only
the portion of their results of operations subsequent to the acquisition dates
is included in the Company's operating results. As a result, comparisons of
results for the years ended June 30, 1997, 1996, and 1995 are not meaningful.

         The Company typically licenses its modeling software products to
customers for terms of either three or five years, planning and scheduling
software for five or twenty-five years, and its IMS, APC and optimization
software products for terms of 99 years. See "Item 1. Business -- Products and
Services." Because in all cases the licenses are noncancelable and do not impose
significant obligations on the Company, the Company recognizes software license
revenues upon shipment in accordance with generally accepted accounting
principles. In the case of license renewals, revenue is recognized upon
execution of a renewal license agreement. The Company recognizes revenues from
customer support ratably over the term of the license. If a customer elects to
pay for a license in annual installments, the Company charges an implicit amount
of interest and recognizes interest income over the term of the license. A
substantial majority of the Company's term licenses have been renewed upon
expiration. However, there can be no assurance that customers will continue to
renew expiring term licenses at the historical rate.

         The Company's revenues historically have been derived principally from
the licensing of software products. Since the acquisitions of DMCC and Setpoint,
the Company has generated a significantly greater amount of consulting revenues
from services for the implementation of its off-the-shelf software products. The
Company recognizes service revenues as services are performed. Service revenues
from fixed-price contracts are recognized on the percentage-of-completion
method, measured by the portion of costs incurred to date as a percentage of the
estimated total (primarily labor) costs for each contract. Service revenues from
time and expense contracts are recognized as the related services are performed.
Training revenues are recognized as services are performed. Services that have
been performed but for which billings have not been made are recorded as
unbilled receivables, and billings for which services have not been performed
are recorded as unearned revenues on the Company's Consolidated Balance Sheets.

         The Company licenses its software in U.S. dollars and certain foreign
currencies. The Company hedges all material foreign currency-denominated
receivables with specific hedge contracts in amounts equal to those receivables.
While the Company has experienced minor foreign currency exchange gains or
losses due to foreign exchange rate fluctuations, the impact of such movements
has not been material in any period. The Company does not expect fluctuations in
foreign currencies to have a significant impact on either its revenues or
expenses in the foreseeable future.

         The Company's operating costs include the amortization of intangible
assets, including goodwill, arising from the acquisitions of DMCC, Setpoint, the
Process Control Division of Cambridge Control Limited, Bechtel Corporation PIMS
and Basil Joffe Associates, Inc. The net balance of these intangible assets as
of June 30, 1997 is approximately $12.8 million and is being amortized over
periods ranging from 18 months to 12 years. The amortization was approximately
$2,528,000 in fiscal 1997 and will be approximately $564,000 for each of the
next fourteen quarters.

         On August 27, 1997 and August 28, 1997 the Company acquired 100% of
the outstanding shares of NeuralWare, Inc. (NeuralWare) and the SAST
Corporation Limited (SAST), both accounted for as pooling-of-interests.
NeuralWare is a provider of neural net technology and SAST is a provider of
dynamic simulation and operator training services. Since the transactions
occurred after the end of the 1997 fiscal year, they had no affect on
operations. See footnote 3(g) "Acquisitions Subsequent to Year End" to "Notes
to Consolidated Financial Statements".

                                       19
<PAGE>   21
          RESULTS OF OPERATIONS

         The following table sets forth the amount and percentage of total
revenues represented by certain consolidated statement of income data for the
periods indicated:

<TABLE>
<CAPTION>
                                                                            Year Ended June 30,
                                                      ------------------------------------------------------------------
                                                              1995                   1996                     1997
                                                      --------------------  --------------------   ---------------------
                                                                           (Dollars in thousands)
<S>                                                   <C>           <C>     <C>            <C>     <C>            <C>  
Revenues:
Software licenses .................................   $ 45,649       79.4%  $  65,644       63.4%  $  97,240       53.9%
  Maintenance and other services ..................     11,849       20.6      37,965       36.6      83,059       46.1
                                                      --------       ----    --------       ----     -------       ----
                                                        57,498      100.0     103,609      100.0     180,299      100.0
                                                      --------       ----    --------       ----     -------       ----
Expenses:
  Cost of software licenses .......................      2,799        4.9       3,476        3.4       4,538        2.5
  Cost of services and other ......................      7,458       13.0      22,949       22.1      48,702       27.0
  Selling and marketing ...........................     23,233       40.4      34,691       33.5      53,517       29.7
  Research and development ........................     11,375       19.8      20,208       19.5      31,153       17.3
  General and administrative ......................      5,132        8.9       9,565        9.2      15,933        8.8
  Charge for in-process research
  and development .................................         --       --        24,421       23.6       8,664        4.8
  Costs related to acquisition ....................        950        1.6          --       --            --       --
                                                      --------       ----    --------       ----     -------       ----
                                                        50,947       88.6     115,310      111.3     162,507       90.1
                                                      --------       ----    --------       ----     -------       ----
                  Income (loss) from operations ...      6,551       11.4     (11,701)     (11.3)     17,792        9.9

Foreign currency exchange gain (loss) .............         34        0.1        (223)      (0.3)       (236)      (0.1)

Income  on equity in joint ventures ...............         22       --            10       --            26       --

Interest income ...................................      3,095        5.4       3,666        3.5       5,323        2.9
Interest expense ..................................       (561)      (1.0)     (1,323)      (1.2)       (151)      (0.1)
                                                      --------       ----    --------       ----     -------       ----

    Income (loss) before provision for income taxes      9,141       15.9      (9,571)      (9.3)     22,754       12.6

Provision for income taxes ........................      3,725        6.5       5,614        5.4       9,599        5.3
                                                      --------       ----    --------       ----     -------       ----

                  Net income (loss) ...............   $  5,416        9.4%  ($ 15,185)     (14.7%)   $13,155        7.3%
                                                      ========       ====    ========       ====     =======       ====
</TABLE>


                                       20
<PAGE>   22
COMPARISON OF FISCAL 1997 TO FISCAL 1996

         The Company acquired DMCC and Setpoint in the third quarter of fiscal
1996 and have subsequently taken steps to integrate and reorganize the
operations. The operations of DMCC and Setpoint at the time of acquisition were
roughly the same size as AspenTech. As a result, the Company's operations for
fiscal 1997 and fiscal 1996 are not directly comparable. In addition the Company
acquired and subsequently integrated four companies in the second quarter of
fiscal 1997: B-Jac International, the Process Control Division of Cambridge
Controls Limited, the planning and scheduling software group of Bechtel
Corporation (PIMS), and Basil Joffe and Associates, Inc. The operations of all
these acquisitions individually and combined is immaterial to the Company's
historical statements.

         Revenues. Revenues are derived from software licenses and services.
Total revenues for fiscal 1997 increased 74.0% to $180.3 million from $103.6 in
fiscal 1996.

         Software license revenues represented 53.9% and 63.4% of total revenues
in fiscal 1997 and 1996, respectively. Revenues from software licenses in fiscal
1997 increased 48.1% to $97.2 million from $65.6 million in fiscal 1996. The
growth in software license revenues was attributable both to internal growth in
existing operations and to additional licenses entered into by the acquired
subsidiaries. The internal growth in software license revenues was attributable
to renewals of software licenses covering existing users, the expansion of
existing customer relationships through licenses covering additional users and
additional software products, and, to a lesser extent, the addition of new
customers. The decrease in software license as a percentage of total revenues
was attributable to the growth of service revenues resulting from the Company's
acquisitions of DMCC and Setpoint.

         Total revenues from customers outside the United States were $94.3
million or 52.3% of total revenues and $47.1 million, or 45.4% of total revenues
for fiscal 1997 and 1996, respectively.

         Revenues from services and other consist of consulting services,
post-contract support on software licenses, training and sales of documentation.
Since the acquisitions of DMCC and Setpoint, the Company has generated a
significantly greater amount of consulting services for the analysis, design and
automation of process manufacturing plants. As a result of the acquisitions and
the subsequent expansion of the combined services execution capability, revenues
from services and other for fiscal 1997 increased 118.8% to $83.1 million from
$38.0 million in fiscal 1996.

         Neither the Company's joint venture and similar activities, nor any
discounting or similar activities has historically had a material effect on the
Company's revenues.

         Cost of Software Licenses. Cost of software licenses consists of
royalties, amortization of previously capitalized software costs, costs related
to delivery of software (including disk duplication and third party software
costs), printing of manuals and packaging. Cost of software licenses for fiscal
1997 increased 30.6% to $4.5 million from $3.5 million in fiscal 1996. Cost of
software licenses as a percentage of revenues from software licenses decreased
to 4.7% in fiscal 1997 from 5.3% in fiscal 1996. This decrease was due to the
spreading of fixed production and delivery costs over a larger revenue base and
to the generation of a greater portion of sales having minimal third-party
royalty costs.

         Cost of Services and Other. Cost of services and other consists of the
cost of execution of application consulting services, technical support
services, the cost of training services and the cost of manuals sold separately.
Cost of services and other in fiscal 1997 increased 112.2% to $48.7 million from
$22.9 million in fiscal 1996. Cost of services and other as a percentage of
revenues from services and other decreased to 58.6% in fiscal 1997 from 60.4% in
fiscal 1996. The percentage decrease reflected not only a change in mix of
services provided by the Company but improvement in the efficiency of project
execution.

         Selling and Marketing. Selling and marketing expenses in fiscal 1997
increased 54.3% to $53.5 million from $34.7 million in fiscal 1996 while
decreasing as a percentage of total revenues to 29.7% from 33.5%. The percentage
decrease in costs reflects the Company's leveraging of its worldwide sales and
technical sales force to market all of the Company's products and services. The
Company continues to invest in sales personnel and regional sales offices to
improve the Company's geographic proximity to its customers, to maximize the
penetration of existing accounts and to add new customers.

         Research and Development. Research and development expenses consist
primarily of personnel and outside consultancy costs required to conduct the
Company's product development efforts. Capitalized research and development
costs are amortized over a three-year period. Research and development costs in
fiscal 1997 increased 54.2% to $31.2 million from $20.2 in fiscal 1996 while
decreasing as a percentage of total revenues to 17.3% from 19.5%. The increase
in costs principally reflects investment in a suite of next generation products
from overlapping technology purchased through the series of acquisitions and a
continued investment in the 


                                       21
<PAGE>   23
Company's core modeling products. The Company capitalized 7.1% and 4.3% of its
total research and development costs during 1997 and 1996 respectively.

         General and Administrative. General and administrative expenses consist
primarily of salaries of administrative, executive, financial, and legal
personnel, outside professional fees and amortization of intangibles. General
and administrative expense in fiscal 1997 increased 66.6% to $15.9 million from
$9.6 million in fiscal 1996, and decreased as a percentage of total revenues to
8.8% from 9.2% in fiscal 1996. The decrease is the result of improvement in the
efficiency of the administrative group over an increasing revenue base.

         Charge for In-Process Research and Development. In the second quarter
of fiscal 1997, the Company recognized a non-recurring charge of $8.7 million
for the write-off of in-process research and development in connection with the
acquisitions of the Process Control Division of Cambridge Controls, LTD., the
planning and scheduling software group of Bechtel Corporation , and Basil Joffe
and Associates, Inc. The Company recognized a similar charge during the third
quarter of fiscal 1996 of $24.4 million in connection with its acquisition of
DMCC and Setpoint.

         Interest Income. Interest income is generated primarily from the sale
of software pursuant to installment contracts for off-line modeling software.
Under these contracts, the Company offers customers the option to make annual
payments for term licenses instead of a single license fee payment at the
beginning of the license term. A substantial majority of the off-line modeling
customers elect to license these products through installment contracts. The
Company believes this election is made principally because the customers prefer
to pay for the Company's off-line modeling products out of their operating
budget, rather than out of their capital budgets. Included in the annual
payments is an implicit interest charge based upon the interest rate established
by the Company at the time of the license. The Company sells a portion of the
installment contracts to unrelated financial institutions. The interest earned
by the Company on the installment contract portfolio in any one year is the
result of the implicit interest established by the Company on installment
contracts and the size of the contract portfolio. Interest income in fiscal 1997
increased 45.2% to $5.3 million from $3.7 million in fiscal 1996. Interest
income increased as a result of investment of the net proceeds of the Company's
public offering completed in June 1996 and a larger installment contract
portfolio.

         Interest Expense. Interest expense is generated from interest charged
on the Company's line of credit, subordinated notes payable to the Massachusetts
Capital Resource Company, a promissory note issued in connection with the
Setpoint acquisition, and capital lease obligations. Interest expense in fiscal
1997 decreased to $0.2 million from $ 1.3 million in fiscal 1996. This decrease
reflects the repayment at the end of fiscal 1996 of borrowings under the
Company's line of credit, the subordinated notes and the promissory note issued 
in connection with the acquisition of Setpoint.

         Provision for Income Taxes. The effective tax rate in fiscal 1997 and
1996 is calculated as a percentage of income before taxes, exclusive of the
non-recurring charges for in-process research and development. The effective tax
rate decreased in fiscal 1997 to 36.0% of pretax income from 37.8% in fiscal
1996. This decrease is primarily due to utilization of various tax credits and
carryforwards.

COMPARISON OF FISCAL 1996 TO FISCAL 1995

         The Company acquired DMCC and Setpoint in the third quarter of fiscal
1996 in purchase transactions and has subsequently taken steps to integrate and
reorganize the operations of AspenTech and its new subsidiaries. As a result,
the Company's operating results for fiscal 1996 and fiscal 1995 are not directly
comparable. The results of the Company's operations for fiscal 1996 are not
representative of results of operations of the combined entities for subsequent
periods. For fiscal 1996, on a pro forma basis giving effect to the acquisitions
of DMCC and Setpoint as of the beginning of the period, revenues from software
licenses and revenues from services and other represented 53% and 47%,
respectively, of total revenues.

         Revenues. Revenues are derived from software licenses and services.
Total revenues for fiscal 1996 increased 80.2% to $103.6 million from $57.5
million in fiscal 1995.

         Software license revenues represented 63.4% and 79.4% of total revenues
in fiscal 1996 and 1995, respectively. Revenues from software licenses in fiscal
1996 increased 43.8% to $65.6 million from $45.6 million in fiscal 1995. The
growth in software license revenues was attributable both to internal growth in
existing operations and to additional licenses entered into by the newly
acquired subsidiaries. The internal growth in software license revenues was
attributable to renewals of software licenses covering existing users, to the
expansion of existing customer relationships through licenses covering
additional users and additional software products, and, to a lesser extent, to
the addition of new customers. The decrease in software license revenues as a
percentage of total revenues was attributable to the growth in service revenues
resulting from AspenTech's acquisitions of DMCC and Setpoint.

         Total revenues from customers outside the United States were $47.1
million or 45.4% of total revenues and $29.8 million or 51.9% of total revenues
for fiscal 1996 and 1995, respectively. The growth in dollar amount of total
revenues from customers outside 


                                       22
<PAGE>   24
the United States was attributable in part to revenues generated by Setpoint
and, to a lesser extent, to internal growth in existing operations.

         Revenues from services and other consist of consulting services,
post-contract support on software licenses, training and sales of documentation.
Since the acquisitions of DMCC and Setpoint, the Company has generated a
significantly greater amount of consulting revenues from services for the
analysis, design and automation of process manufacturing plants. As a result,
revenues from services and other for fiscal 1996 increased 220.4% to $38.0
million from $11.8 million in fiscal 1995.

         Cost of Software Licenses. Cost of software licenses for fiscal 1996
increased 24.2% to $3.5 million from $2.8 million in fiscal 1995. Cost of
software licenses as a percentage of revenues from software licenses decreased
to 5.3% in fiscal 1996 from 6.1% in fiscal 1995. This decrease was due to the
spreading of fixed production and delivery costs over a larger revenue base and
to the generation of a greater portion of sales having minimal third-party
royalty costs.

         Cost of Services and Other. Cost of services and other in fiscal 1996
increased 207.7% to $22.9 million from $7.5 million in fiscal 1995. Cost of
services and other as a percentage of revenues from services and other decreased
to 60.4% in fiscal 1996 from 62.9% in fiscal 1995. The percentage decrease
reflected a change in the mix of services provided by the Company, primarily as
a result of the acquisitions of DMCC and Setpoint.

         Selling and Marketing. Selling and marketing expenses in fiscal 1996
increased 49.3% to $34.7 million from $23.2 million in fiscal 1995 while
decreasing as a percentage of total revenues to 33.5% from 40.4%. The percentage
decrease in costs reflects the lower level of sales and marketing activities
historically supported by DMCC and Setpoint, as well as the Company's leveraging
of its existing worldwide sales and technical sales force to market the software
products and services of the newly acquired companies.

         Research and Development. Research and development expenses in fiscal
1996 increased 77.7% to $20.2 million from $11.4 million in fiscal 1995 while
decreasing as a percentage of total revenues to 19.5% from 19.8%. The increase
in costs principally reflects continued investment in development of the
Company's core modeling products and a common software architecture encompassing
the Company's expanded family of software products, as well as a reduction in
the amount of research and development capitalized during the period. The
Company capitalized 4.3% and 8.1% of its total research and development costs
during fiscal 1996 and 1995, respectively.

         General and Administrative. General and administrative expenses in
fiscal 1996 increased 86.4% to $9.6 million from $5.1 in fiscal 1995, and
increased as a percentage of total revenues to 9.2% from 8.9% in fiscal 1995.
The dollar increase principally reflected the growth in the scale and scope of
the Company's operations.

         Charge for In-Process Research and Development. In the third quarter of
fiscal 1996, the Company recognized a non-recurring charge of $24.4 million for
the write-off of in-process research and development in connection with its
acquisitions of DMCC and Setpoint.

         Interest Income. Interest income in fiscal 1996 increased 18.4% to $3.7
million from $3.1 million in fiscal 1995. Interest income increased as a result
of investment of the net proceeds of public offerings completed by the Company
in November 1994, February 1995, and June 1996, a larger installment contract
portfolio and an increase in the implicit interest rate charged to customers.

         Interest Expense. Interest expense in fiscal 1996 increased to $1.3
million from $0.6 million in fiscal 1995. This increase principally reflected a
higher level of borrowings under the Company's bank line of credit as a result
of borrowings used for payment of a portion of the purchase price for the
Setpoint acquisition.

         Provision for Income Taxes. The effective tax rate in fiscal 1996 is
calculated as a percentage of income before taxes, exclusive of the
non-recurring charge for in-process research and development. The effective tax
rate decreased in fiscal 1996 to 37.8% of pretax income from 40.8% in fiscal
1995. This percentage decrease related principally to non-deductible acquisition
costs incurred in connection with the ISI acquisition in fiscal 1995.


QUARTERLY RESULTS

         The Company's operating results have fluctuated in the past and may
fluctuate significantly in the future. Because the Company ships software
products within a short period after receipt of an order, the Company typically
does not have a material backlog of unfilled orders for software products, and
revenues from software licenses in any quarter are substantially dependent on
orders for software products booked in the quarter. Historically, a majority of
each quarter's revenues from software licenses has come from license contracts
that have been effected in the final weeks of that quarter.

         The revenues for a quarter typically include a number of large orders.
If the timing of any of these orders is delayed, it could result in a
substantial reduction in revenues for that quarter. Since the Company's expense
levels are based in part on its expectations as 


                                       23
<PAGE>   25
to future revenues, the Company may be unable to adjust spending in a timely
manner to compensate for any revenue shortfall. Accordingly, any revenue
shortfalls would likely have a disproportionate adverse effect on net income.

         Prior to fiscal 1996, the Company experienced a net loss for the first
quarter of each fiscal year, in part because a substantial portion of the
Company's revenues is derived from countries other than the United States where
business is slow during the summer months, and also in part because of the
timing of contract renewals. The Company expects that these factors will
continue to affect its operating results. See "Item 1a. Risk Factors -
Fluctuations in Quarterly Operating Results."

         In addition, in recent years the Company's revenues during the third
fiscal quarter, as compared to the immediately preceding quarter, have grown at
a slower rate than during the second and fourth fiscal quarters, as compared to
their respective immediately preceding quarters. The Company's operating results
for the third quarter of fiscal 1996 included a non-recurring charge for
in-process research and development of $24.4 million recorded in connection with
the acquisitions of DMCC and Setpoint.

         The following table presents selected quarterly statement of income
data for fiscal 1995, fiscal 1996 and fiscal 1997. These data are unaudited but,
in the opinion of the Company's management, reflect all adjustments that the
Company considers necessary for a fair presentation of these data in accordance
with generally accepted accounting principles. As a result of the acquisitions
of DMCC and Setpoint in purchase transactions during the quarter ended March 31,
1996, the quarterly results presented below are not indicative of future results
of operations.

<TABLE>
<CAPTION>
                                                                                     QUARTER ENDED
                                                -----------------------------------------------------------------------------------
                                                         FISCAL 1996                                      FISCAL 1997
                                                -----------------------------------------------------------------------------------
                                                Sept.30     Dec.31     Mar.31    June 30    Sept.30     Dec.31    Mar.31    June 30
                                                --------   --------   --------   --------   --------   --------   -------  --------
<S>                                             <C>        <C>        <C>        <C>        <C>        <C>        <C>      <C>     
Revenues:
  Software licenses ..........................  $  9,927   $ 13,980   $ 17,923   $ 23,814   $ 16,131   $ 23,928   $26,656  $ 30,525
  Maintenance and other services .............     3,342      3,960     13,169     17,494     18,737     20,273    21,320    22,729
                                                --------   --------   --------   --------   --------   --------   -------  --------
                                                  13,269     17,940     31,092     41,308     34,868     44,201    47,976    53,254
Expenses:
  Cost of software licenses ..................       591        972        938        975        816      1,268     1,183     1,271
  Cost of maintenance and other services .....     1,847      2,140      8,397     10,565     11,129     11,984    12,464    13,125
  Selling and marketing ......................     6,033      7,071      9,631     11,956     11,286     12,953    14,207    15,071
  Research and development ...................     3,457      3,731      5,834      7,186      6,964      7,141     7,861     9,187
  General and administrative .................     1,288      1,375      3,133      3,769      3,721      3,959     4,342     3,911
  Charge for in-process research 
   and development ...........................        --         --     24,421         --         --      8,664        --        --
                                                --------   --------   --------   --------   --------   --------   -------  --------
                                                  13,216     15,289     52,354     34,451     33,916     45,969    40,057    42,565
             Income (loss) from operations ...        53      2,651    (21,262)     6,857        952     (1,768)    7,919    10,689

Other income (expense) .......................       (56)       (17)       (69)       (71)       (22)       (88)       --      (100)
Interest income, net .........................       870        877        434        162      1,345      1,236     1,126     1,465
Income (loss) before provision for
income taxes .................................       867      3,511    (20,897)     6,948      2,275       (620)    9,045    12,054
Provision for income
taxes ........................................       329      1,349      1,339      2,597        865      1,341     3,418     3,975
                                                --------   --------   --------   --------   --------   --------   -------  --------

 Net income (loss) ...........................  $    538   $  2,162   $(22,236)  $  4,351   $  1,410   $ (1,961)  $ 5,627  $  8,079
                                                ========   ========   ========   ========   ========   ========   =======  ========
</TABLE>


                                       24
<PAGE>   26
LIQUIDITY AND CAPITAL RESOURCES

         In recent years, the Company has financed its operations principally
through cash generated from sales of securities through private placements and
public offerings of its Common Stock, operating activities, the sale of
installment contracts to third parties and, at certain times during the year,
borrowings under a bank line of credit.

         In the fourth quarter of fiscal 1996 and in the second and third
quarters of fiscal 1995, the Company received a total of approximately $87.0
million of net proceeds from its initial public offering and subsequent public
offerings. A portion of the total net proceeds was used for working capital and
other general corporate purposes, to pay a portion of the purchase prices of
DMCC and Setpoint and to repay outstanding indebtedness under its bank line of
credit, subordinated notes and a promissory note issued in conjunction with the
purchase of Setpoint. The Company evaluates on an ongoing basis potential
opportunities to acquire or invest in technologies, products or businesses that
expand, complement or are otherwise related to the Company's current business
and products. See "Item 1a. Risk Factors - Risks Associated with Future
Acquisitions."

         In fiscal 1997, operating activities provided $0.8 million of cash
primarily as a result of net income, increases in accounts payable, accrued
expenses and deferred revenue offset in part by increases in long-term
installments receivable and accounts receivable. In fiscal 1996 and 1995,
operating activities provided $18.4 million and $3.6 million of cash,
respectively, primarily related to net income and increases in accounts payable,
accrued expenses and deferred revenue, offset in part by increases in accounts
receivable.

         In recent years, the Company has had arrangements to sell long-term
contracts to two financial institutions, General Electric Capital Corporation
and Sanwa Business Credit Corporation. These contracts represent amounts due
over the life of existing term licenses. During fiscal 1997, installment
contracts increased by $20.3 million to $50.0 million, net of $30.2 million of
installment contracts sold to General Electric Capital Corporation and Sanwa
Business Credit Corporation. During fiscal 1996, installment contracts decreased
by $1.8 million to $29.8 million, net of $28.9 million of installment contracts
sold to General Electric Capital Corporation and Sanwa Business Credit
Corporation. The Company's arrangements with these two financial institutions
provide for the sale of installment contracts up to certain limits and with
certain recourse obligations. At June 30, 1997 and June 30, 1996, the balance of
the uncollected principal portion of the contracts sold to these two financial
institutions was $57.8 million and $42.7 million, respectively, for which the
Company had partial recourse obligations of $6.6 million and $11.5 million,
respectively. The availability under these arrangements will increase as the
financial institutions receive payment on installment contracts previously sold.
See Note 12 of Notes to Consolidated Financial Statements.

         The Company maintains a $30.0 million bank line of credit, expiring on
December 31, 1998, that provides for borrowings of specified percentages of
eligible accounts receivable and eligible current installment contracts.
Advances under the line of credit bear interest at a rate (8.5% at June 30,
1997) equal to the bank's prime rate plus a specified margin or, at the
Company's option, a rate (5.69% at June 30, 1996) equal to a defined LIBOR plus
a specified margin. The bank line of credit is secured by a pledge of
substantially all of the assets of the Company and its United States
subsidiaries. The line of credit agreement requires the Company to provide the
bank with certain periodic financial reports and to comply with certain
financial tests, including maintenance of minimum levels of consolidated net
income before taxes and of the ratio of current assets to current liabilities.
As of June 30, 1997, there were no outstanding borrowings under the line of
credit.

         The Company's commitments as of June 30, 1997 consisted primarily of
leases on its headquarters and other facilities. See "Item 1. Business --
Facilities." There were no other material commitments for capital or other
expenditures. The Company believes its current cash balances, availability of
sales of its installment contracts, availability under its bank line of credit
and cash flows from its operations, will be sufficient to meet its working
capital and capital expenditure requirements for at least the next 12 months.

INFLATION

         Inflation has not had a significant impact on the Company's operating
results to date, nor does the Company expect it to have significant impact
during fiscal 1998.



ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

The Financial Statements of the Company are listed in the Index to Financial
Statements filed in Item 14(a)(i) as part of this Form 10-K.


                                       25
<PAGE>   27
ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS OF ACCOUNTING AND
         FINANCIAL DISCLOSURE

         There have been no changes or disagreements with accountants on
accounting or financial disclosure matters during the Company's two most recent
fiscal years.


                                    PART III

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

         DIRECTORS

         Certain of the information concerning the directors of the Company
required under this Item is contained in "Item 4a. Executive Officers of the
Registrant," and the remainder of such information is incorporated herein by
reference to the Company's definitive proxy statement pursuant to Regulation
14A, to be filed with the Securities and Exchange Commission not later than 120
days after June 30, 1997, under the heading "Election of Directors."

         EXECUTIVE OFFICERS

         Certain of the information concerning the executive officers of the
Company required under this Item is contained in "Item 4a. Executive Officers of
the Registrant," and the remainder of such information is incorporated herein by
reference to the Company's definitive proxy statement pursuant to Regulation
14A, to be filed with the Securities and Exchange Commission not later than 120
days after June 30, 1997, under the heading "Election of Directors."

ITEM 11. EXECUTIVE COMPENSATION

         The information required under this Item is incorporated herein by
reference to the Company's definitive proxy statement pursuant to Regulation
14A, to be filed with the Securities and Exchange Commission not later than 120
days after June 30, 1997, under the heading "Executive Officer Compensation."


ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

         The information required under this Item is incorporated herein by
reference to the Company's definitive proxy statement pursuant to Regulation
14A, to be filed with the Securities and Exchange Commission not later than 120
days after June 30, 1997, under the heading "Share Ownership of Principal
Stockholders and Management."

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

         The information required under this Item is incorporated herein by
reference to the Company's definitive proxy statement pursuant to Regulation
14A, to be filed with the Securities and Exchange Commission not later than 120
days after June 30, 1997, under the heading "Certain Relationships and Related
Transactions.".


                                       26
<PAGE>   28
                                     PART IV

ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K


(a)(1)    Financial Statements                                             Page
          --------------------                                             ----

       -  Report of Independent Public Accountants                         F-2
       -  Consolidated Financial Statements:
       -  Balance Sheets as of June 30, 1996 and 1997                      F-3
       -  Statements of Operations for the years ended
             June 30, 1995, 1996 and 1997                                  F-4

       -  Statements of Stockholders' Equity for the
             years ended June 30, 1995, 1996 and 1997                      F-5

       -  Statements of Cash Flows for the years ended
             June 30, 1995, 1996 and 1997                                  F-6

       -  Notes to Consolidated Financial Statements                       F-7


(a)(2)     Financial Statement Schedules
           -----------------------------

           Report of Independent Public Accountants on Schedule            S-1
           II  - Valuation and Qualifying Accounts                         S-2

All other schedules are omitted because they are not required or the required
information is shown in the consolidated financial statements or notes thereto.

       (a)(3)     Exhibits

      *       3.1     - Restated Articles of Organization of the Registrant.

     **       3.2     - By-laws of Registrant.

    ***       4.1     - Specimen Certificate for Shares of the Registrant's 
                        Common Stock, $.10 par value.

    ***       10.1    - Lease Agreement between Registrant and Teachers 
                        Insurance and Annuity Association of America regarding
                        Ten Canal Park, Cambridge, Massachusetts.

    ***       10.2    - System License Agreement between the Registrant and the
                        Massachusetts Institute of Technology, dated March 30, 
                        1982, as amended.

    ***+      10.3    - Non-Equilibrium Distillation Model Development and
                        License Agreement between the Registrant and Koch
                        Engineering Company, Inc., as amended.

    ***+      10.3a. -  Letter, dated October 19, 1994, from the Company to Koch
                        Engineering Company, Inc., pursuant to which the Company
                        elected to extend the term of the Company's license
                        under the Non-Equilibrium Distillation Model Development
                        and License Agreement.

    ***+      10.4    - Batch Distillation Computer Program Development and
                        license agreement between Process Simulation Associates,
                        Inc. and Koch Engineering Company, Inc.

    ***+      10.5    - Agreement between the Registrant and Imperial College of
                        Science, Technology and Medicine regarding Assignment of
                        SPEEDUP. 

              10.6  *** (a)   Subordinated Note and Warrant Purchase
                              Agreement dated as of May 7, 1991 between the
                              Registrant and Massachusetts Capital Resource
                              Company.

                    *** (b)   Subordinated Note due 1998 dated as of May 7, 1991
                              issued by Registrant to Massachusetts Capital 
                              Resource Company.

                    *** (c)   Common Stock Purchase Warrant No. 91-1.

                    *** (d)   Common Stock Purchase Warrant No. 91-2.

                    *** (e)   Subordinated Note Purchase Agreement dated as of 
                              August 22, 1994 between the Registrant and
                              Massachusetts Capital Resource Company.

                    *** (f)   Subordinated Note due 1997 dated as of August 22, 
                              1994 issued by Registrant to Massachusetts Capital
                              Resource Company.

                    *** (g)   Security Agreement dated as of July 24, 1989
                              between the Registrant and Massachusetts Capital
                              Resource Company, as amended.

         ***  10.7    - Noncompetition, Confidentiality and Proprietary Rights
                        Agreement between the Registrant and Lawrence B. Evans.

         ***  10.8    - Noncompetition, Confidentiality and Proprietary Rights
                        Agreement between the Registrant and Joseph F. Boston.

         ***  10.9    - Noncompetition, Confidentiality and Proprietary Rights
                        Agreement between the Registrant and Paul W. Gallier.

         ***  10.10   - Noncompetition, Confidentiality and Proprietary Rights
                        Agreement between the Registrant and Herbert I. Britt.

         ***  10.11   - 1988 Non-Qualified Stock Option Plan, as amended.

          ++  10.12   - 1995 Stock Option Plan


                                       27
<PAGE>   29
          ++  10.13   - 1995 Directors Stock Option Plan

          ++  10.14   - 1995 Employees Stock Purchase Plan

              10.15   + ***(a)      Vendor Program Agreement between the 
                                    Registrant and General Electric Capital
                                    Corporation.

                          *(b)      Rider No. 1, dated December 14, 1994, to 
                                    Vendor Program Agreement between the
                                    Registrant and General Electric Capital
                                    Corporation.

        ***+  10.16   - Letter Agreement between the Registrant and Sanwa
                        Business Credit Corporation.

         ***  10.17   - Form of Employee Confidentiality and Non-Competition 
                        Agreement.

         ***  10.18   - Equity Joint Venture Contract between the Registrant and
                        China Petrochemical Technology Company.

        ****  10.19   - Amended and Restated Agreement and Plan of
                        Reorganization, dated as of May 12, 1995, by and among
                        the Registrant, Industrial Systems, Inc. and the
                        stockholders of Industrial Systems, Inc.

        ***** 10.20   - Stock Purchase Agreement dated as of December 15, 1995,
                        among Aspen Technology, Inc., Dynamic Matrix Control
                        Corporation and Charles R. Cutler, June A. Cutler,
                        Charles R. Johnston and Cheryl Lynne Johnston, as
                        shareholders of Dynamic Matrix Control Corporation.

        ***** 10.21   - Share Purchase Agreement dated as of January 5, 1996
                        among Aspen Technology, Inc., Amelinc Corporation and
                        Cegelec S.A.

              10.22   - Further Amended and Restated Revolving Credit Agreement
                        dated as of February 15, 1996 among the Registrant,
                        Prosys Modeling Investment Corporation, Industrial
                        Systems, Inc., Dynamic Matrix Control Corporation and
                        Setpoint, Inc., as the Borrowers, the Lenders Parties
                        thereto, and Fleet Bank of Massachusetts, N.A., as Agent
                        and Lender, together with related forms of the following
                        (each in the form executed by each of such Borrowers):

                    *****(a)  Amended and Restated Revolving Credit Note

                    *****(b)  Patent Conditional Assignment and Security 
                              Agreement

                    *****(c)  Trademark Collateral Security Agreement.

                    *****(d)  Security Agreement.

             10.23     - 1996 Special Stock Option Plan

             10.24     - Change in Control Agreement between the Registrant and
                         Lawrence B. Evans dated August 12, 1997.

             10.25     - Change in Control Agreement between the Registrant and
                         Joseph F. Boston dated August 12, 1997.

             10.26     - Change in Control Agreement between the Registrant and
                         David McQuillin dated August 12, 1997.

             10.27     - Change in Control Agreement between the Registrant and
                         Mary A. Palermo dated August 12, 1997.

             10.28     - Change in Control Agreement between the Registrant and
                         Joel B. Rosen dated August 12, 1997.

             10.29     - Change in Control Agreement between the Registrant and
                         Stephen J. Doyle dated August 12, 1997.

              22.1     - Subsidiaries of the Registrant.

              23.1     - Consent of Arthur Andersen LLP.

              24.1     - Power of Attorney (included in signature page to
                         Form 10-K).



             27        -Financial Data Schedules for fiscal year ended 
                        June 30, 1997.

          *       Incorporated by reference to the corresponding Exhibit to the
                  Registration Statement on Form S-1 of the Registrant 
                  (Registration No. 32-88734) filed on January 29, 1995.

        **        Incorporated by reference to Exhibit 3.3 to the Registration
                  Statement on Form S-1 of the Registrant (Registration No.
                  33-83916) filed on September 13, 1994.

       ***        Incorporated by reference to the corresponding Exhibit to the
                  Registration Statement on Form S-1 of the Registrant
                  (Registration No. 33-83916) filed on September 13, 1994.

      ****        Incorporated by reference to Exhibit 10.1 to the Registrant's
                  Quarterly Report on form 10-Q for the fiscal quarter ended
                  March 31, 1995.

     *****        Incorporated by reference to the corresponding Exhibit to the
                  Registrant's Current Report on Form 8-K dated January 5, 1996,
                  as amended, by Amendment Nos. 1,2,3 and 4 thereto.
                  Incorporated by reference to the corresponding Exhibit to the
                  Registrant's Quarterly Report on Form 10-Q for the quarter
                  ended March 31, 1996. Incorporated by reference to the
                  corresponding Exhibit to the Registration Statement on Form
                  S-8 of the Registrant (Registration No. 333-11651) filed on
                  September 9, 1996.

         +        Certain portions have been granted Confidential Treatment by
                  the Securities and Exchange Commission at the request of the
                  Company pursuant to Rule 406 under the Securities Act of 1933.


        ++        Incorporated by reference to the corresponding Exhibit to the
                  Registrant's Annual Report on Form 10-K for the fiscal year
                  ending June 30, 1996.
 
(b)      Reports on Form 8-K

                  No reports on Form 8-K have been filed during the last fiscal 
quarter of 1997.


                                       28
<PAGE>   30
                                   SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities and
Exchange Act of 1934, the Registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized, this 29th day of
September, 1997.



                                     ASPEN TECHNOLOGY, INC.

                                     /s/ Lawrence B. Evans   
                                     ------------------------------------------
                                     Lawrence B. Evans, Chairman of the Board of
                                     Directors and Chief Executive Officer





                                POWER OF ATTORNEY

Each person whose signature appears below hereby appoints Lawrence B. Evans and
Mary A. Palermo and each of them severally, acting alone and without the other,
his/her true and lawful attorney-in fact with the authority to execute in the
name of each such person, and to file with the Securities and Exchange
Commission, together with any exhibits thereto and other documents therewith,
any and all amendments to this Annual Report of Form 10-K necessary or advisable
to enable the Registrant to comply with the rules, regulations, and requirements
of the Securities Act of 1934, as amended, in respect thereof, which amendments
may make such other changes in the Annual Report as the aforesaid
attorney-in-fact executing the same deems appropriate.

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended,
this Registration Statement has been signed by the following persons in the
capacities indicated on the 29th day of September, 1997.


                                       29
<PAGE>   31
            SIGNATURE                       TITLE(S)
- ------------------------------   -----------------------------------------------


/s/ Lawrence B. Evans            Chairman of the Board and Chief Executive
- ------------------------------   Officer (Principal Executive Officer) 
Lawrence B. Evans                 


                                  
                                  
/s/ Mary A. Palermo               Executive Vice President, Finance and Chief 
- ------------------------------    Financial Officer (Principal Financial and  
Mary A. Palermo                   Accounting Officer)


/s/ Joseph F. Boston              Director
- ------------------------------
Joseph F. Boston

/s/ Gresham T. Brebach, Jr.       Director
- ------------------------------
Gresham T. Brebach, Jr.


/s/ Douglas R. Brown              Director
- ------------------------------
Douglas R. Brown


/s/ Joan C. McArdle               Director
- ------------------------------
Joan C. McArdle


/s/Alison Ross                    Director
- ------------------------------
Alison Ross


                                        30
<PAGE>   32
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES

                   INDEX TO CONSOLIDATED FINANCIAL STATEMENTS




                                                                            PAGE

REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS                                    F-2

CONSOLIDATED BALANCE SHEETS AS OF JUNE 30, 1996 AND 1997                    F-3

CONSOLIDATED STATEMENTS OF OPERATIONS FOR THE YEARS ENDED
JUNE 30, 1995, 1996 AND 1997                                                F-4

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY FOR THE
YEARS ENDED JUNE 30, 1995, 1996 AND 1997                                    F-5

CONSOLIDATED STATEMENTS OF CASH FLOWS FOR THE YEARS ENDED
JUNE 30, 1995, 1996 AND 1997                                                F-6

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS                                  F-7


                                      F-1
<PAGE>   33
                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS



To Aspen Technology, Inc.:

We have audited the accompanying consolidated balance sheets of Aspen
Technology, Inc. (a Massachusetts corporation) and subsidiaries as of June 30,
1996 and 1997, and the related consolidated statements of operations,
stockholders' equity and cash flows for each of the three years in the period
ended June 30, 1997. These financial statements are the responsibility of the
Company's management. Our responsibility is to express an opinion on these
financial statements based on our audits.

We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of Aspen Technology, Inc. and
subsidiaries as of June 30, 1996 and 1997, and the results of their operations
and their cash flows for each of the three years in the period ended June 30,
1997, in conformity with generally accepted accounting principles.







Boston, Massachusetts
August 13, 1997 (Except
with respect to the matters
discussed in footnote 3(g)
as to which the date is
August 28, 1997)


                                      F-2
<PAGE>   34
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                           CONSOLIDATED BALANCE SHEETS
                        (IN THOUSANDS, EXCEPT SHARE DATA)



<TABLE>
<CAPTION>
                                                                                         JUNE 30,          
                      ASSETS                                                         1996        1997 
<S>                                                                               <C>         <C>     
CURRENT ASSETS:
   Cash and cash equivalents                                                      $ 12,524    $ 16,091
   Short-term investments                                                           38,559      15,843
   Accounts receivable, net of reserves of $731 in 1996 and $720 in 1997            38,006      44,180
   Unbilled services                                                                 7,634      12,444
   Current portion of long-term installments receivable, net of unamortized
    discount of $930 in 1996 and $815 in 1997                                       12,068      19,063
   Prepaid expenses and other current assets                                         3,318       7,403
                                                                                  --------    --------

        Total current assets                                                       112,109     115,024
                                                                                  --------    --------

LONG-TERM INSTALLMENTS RECEIVABLE, NET OF UNAMORTIZED DISCOUNT OF $5,027 IN
1996 AND $7,386 IN 1997                                                             17,708      30,963
                                                                                  --------    --------

PROPERTY AND LEASEHOLD IMPROVEMENTS, AT COST:
  Building and improvements                                                          3,741       3,922
  Computer equipment                                                                17,862      23,393
  Purchased software                                                                 2,974       9,852
  Furniture and fixtures                                                             3,489       7,553
  Leasehold improvements                                                               698       2,618
                                                                                  --------    --------
                                                                                    28,764      47,338

  Less--Accumulated depreciation and amortization                                   11,949      19,904
                                                                                  --------    --------
                                                                                    16,815      27,434
                                                                                  --------    --------
COMPUTER SOFTWARE DEVELOPMENT COSTS, NET OF ACCUMULATED AMORTIZATION OF $3,908
IN 1996 AND $5,051 IN 1997                                                           1,817       3,058
                                                                                  --------    --------


LAND                                                                                   925         925
                                                                                  --------    --------

INTANGIBLE ASSETS, NET OF ACCUMULATED AMORTIZATION
OF $819 IN 1996 AND $3,347 IN 1997                                                   9,129      12,768
                                                                                  --------    --------

OTHER ASSETS                                                                         1,664       2,092
                                                                                  --------    --------

                                                                                  $160,167    $192,264
                                                                                  ========    ========
</TABLE>

<TABLE>
<CAPTION>
                                                                                          JUNE 30,
               LIABILITIES AND STOCKHOLDERS' EQUITY                                  1996         1997
<S>                                                                               <C>          <C>
CURRENT LIABILITIES:
   Current portion of capital lease obligations                                   $    425    $    288
   Accounts payable                                                                  6,037       6,712
   Accrued expenses                                                                 16,012      16,572
   Unearned revenue                                                                  8,967       4,294
   Deferred revenue                                                                  8,953      14,372
   Deferred income taxes                                                             2,798       1,775
                                                                                  --------    --------

        Total current liabilities                                                   43,192      44,013
                                                                                  --------    --------

CAPITAL LEASE OBLIGATIONS,
LESS CURRENT PORTION                                                                   706         462
                                                                                  --------    --------

DEFERRED REVENUE, LESS CURRENT PORTION                                               8,279       9,441
                                                                                  --------    --------

OTHER LIABILITIES                                                                    1,757         942
                                                                                  --------    --------

DEFERRED INCOME TAXES                                                                6,398       5,965
                                                                                  --------    --------

COMMITMENTS AND CONTINGENCIES (Notes 11, 12 and 13)

STOCKHOLDERS' EQUITY:
  Common stock, $.10 par value-
    Authorized--40,000,000 shares
    Issued--19,382,360 shares and 20,359,892 shares in 1996 and
      1997, respectively                                                             1,938       2,036
  Additional paid-in capital                                                       109,857     127,578
  Retained (deficit) earnings                                                      (11,094)      2,588
  Cumulative translation adjustment                                                   (362)       (255)
  Treasury stock, at cost--230,396 shares and 230,330 shares of
    common stock in 1996 and 1997, respectively                                       (502)       (502)
  Unrealized loss on investments                                                        (2)         (4)
                                                                                  --------    --------

        Total stockholders' equity                                                  99,835     131,441
                                                                                  --------    --------

                                                                                  $160,167    $192,264
                                                                                  ========    ========
</TABLE>

  The accompanying notes are an integral part of these consolidated financial
                                  statements.


                                      F-3
<PAGE>   35
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES

                      CONSOLIDATED STATEMENTS OF OPERATIONS

                 (IN THOUSANDS, EXCEPT SHARE AND PER SHARE DATA)



<TABLE>
<CAPTION>
                                                                     YEARS ENDED JUNE 30,
                                                            1995             1996             1997
<S>                                                    <C>              <C>              <C>         
REVENUES:
  Software licenses                                    $     45,649     $     65,644     $     97,240
  Services and other                                         11,849           37,965           83,059
                                                       ------------     ------------     ------------

                                                             57,498          103,609          180,299
                                                       ------------     ------------     ------------
EXPENSES:
  Cost of software licenses                                   2,799            3,476            4,538
  Cost of services and other                                  7,458           22,949           48,702
  Selling and marketing                                      23,233           34,691           53,517
  Research and development                                   11,375           20,208           31,153
  General and administrative                                  5,132            9,565           15,933
  Charge for in-process research and development                 --           24,421            8,664
  Costs related to acquisition                                  950               --               --
                                                       ------------     ------------     ------------

                                                             50,947          115,310          162,507
                                                       ------------     ------------     ------------

        Income (loss) from operations                         6,551          (11,701)          17,792

FOREIGN CURRENCY EXCHANGE GAIN (LOSS)                            34             (223)            (236)

INCOME ON EQUITY IN JOINT VENTURES                               22               10               26

INTEREST INCOME                                               3,095            3,666            5,323

INTEREST EXPENSE ON SUBORDINATED NOTES PAYABLE TO A            (369)            (377)              --
RELATED PARTY

OTHER INTEREST EXPENSE                                         (192)            (946)            (151)
                                                       ------------     ------------     ------------

        Income (loss) before provision for income             9,141           (9,571)          22,754
        taxes

PROVISION FOR INCOME TAXES                                    3,725            5,614            9,599
                                                       ------------     ------------     ------------

        Net income (loss)                              $      5,416     $    (15,185)    $     13,155
                                                       ============     ============     ============

NET INCOME (LOSS) PER COMMON AND COMMON EQUIVALENT     $       0.35     $      (0.96)    $       0.63
SHARE                                                  ============     ============     ============


WEIGHTED AVERAGE NUMBER OF COMMON AND COMMON             15,562,042       15,857,472       20,967,200
EQUIVALENT SHARES OUTSTANDING                          ============     ============     ============
</TABLE>

  The accompanying notes are an integral part of these consolidated financial
                                  statements.


                                      F-4
<PAGE>   36
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                 CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY

                        (IN THOUSANDS, EXCEPT SHARE DATA)

<TABLE>
<CAPTION>
                                                              CLASS A, CLASS B                      COMMON STOCK              
                                                               AND SERIES C-1                 NUMBER            $.10          '
                                                                 CONVERTIBLE                 OF SHARES        PAR VALUE       
                                                               PREFERRED STOCK                                                
                                                          NUMBER                                                              
                                                         OF SHARES        PAR VALUE                                           
<S>                                                     <C>               <C>               <C>              <C>              
BALANCE, JUNE 30, 1994                                     356,986        $      177         7,009,330       $      701       
  Issuance of common stock in public offerings,                 --                --         3,100,000              310       
    net of issuance costs of $1,223
  Issuance of common stock under employee stock                 --                --            72,064                7       
    purchase plans
  Exercise of stock options and warrants                        --                --           688,462               69       
  Liquidation of fractional shares                              --                --                --               --       
  Conversion of preferred stock to common stock           (356,986)             (177)        4,709,580              471       
  Purchase of treasury stock                                    --                --                --               --       
  Repayment of receivable                                       --                --                --               --       
  Translation adjustment                                        --                --                --               --       
  Unrealized market gain on investments                         --                --                --               --       
  Tax benefit related to stock options                          --                --                --               --       
  Dividend distributions to stockholders relating               --                --                --               --       
    to acquired Subchapter S corporation, net
  Net income                                                    --                --                --               --       
                                                        ----------        ----------        ----------       ----------       
BALANCE, JUNE 30, 1995                                          --                --        15,579,436            1,558       
  Issuance of common stock in a public offering,                --                --         2,907,820              291       
    net of issuance costs of $4,239
  Issuance of common stock in a private placement               --                --            66,770                6       
  Issuance of common stock under employee stock                 --                --            50,220                5       
    purchase plans
  Exercise of stock options and warrants                        --                --           778,114               78       
  Translation adjustment                                        --                --                --               --       
  Realized gain on investments                                  --                --                --               --       
  Unrealized market loss on investments                         --                --                --               --       
  Tax benefit related to stock options                          --                --                --               --       
  Net loss                                                      --                --                --               --       
                                                        ----------        ----------        ----------       ----------       
BALANCE, JUNE 30, 1996                                          --                --        19,382,360            1,938       
  Issuance of common stock in an immaterial                     --                --           104,162               10       
    pooling
  Issuance of common stock in the purchase of                   --                --           155,740               16       
    businesses
  Issuance of common stock under employee stock                 --                --           210,085               21       
    purchase plans
  Exercise of stock options and warrants                        --                --           507,545               51       
  Translation adjustment                                        --                --                --               --       
  Issuance of treasury stock to charity                         --                --                --               --       
  Unrealized market loss on investments                         --                --                --               --       
  Tax benefit related to stock options                          --                --                --               --       
  Net income                                                    --                --                --               --       
                                                        ----------        ----------        ----------       ----------       
BALANCE, JUNE 30, 1997                                          --        $       --        20,359,892       $    2,036       
                                                        ==========        ==========        ==========       ==========       
</TABLE>

<TABLE>
<CAPTION>
                                                        ADDITIONAL         RETAINED         CUMULATIVE        RECEIVABLE        
                                                          PAID-IN          EARNINGS         TRANSLATION          FROM           
                                                          CAPITAL          (DEFICIT)        ADJUSTMENT        STOCKHOLDER       
                                                                                                                  FOR           
                                                                                                                 STOCK          
                                                                                                                 ISSUED
<S>                                                     <C>               <C>               <C>               <C>               
BALANCE, JUNE 30, 1994                                  $   17,578        $     (398)       $     (390)       $      (15)       
  Issuance of common stock in public offerings,             17,539                --                --                --        
    net of issuance costs of $1,223
  Issuance of common stock under employee stock                238                --                --                --        
    purchase plans
  Exercise of stock options and warrants                     1,113                --                --                --        
  Liquidation of fractional shares                              --                --                --                --        
  Conversion of preferred stock to common stock               (294)               --                --                --        
  Purchase of treasury stock                                    --                --                --                --        
  Repayment of receivable                                       --                --                --                15        
  Translation adjustment                                        --                --                90                --        
  Unrealized market gain on investments                         --                --                --                --        
  Tax benefit related to stock options                         486                --                --                --        
  Dividend distributions to stockholders relating               --              (927)               --                --        
    to acquired Subchapter S corporation, net
  Net income                                                    --             5,416                --                --        
                                                        ----------        ----------        ----------        ----------        
BALANCE, JUNE 30, 1995                                      36,660             4,091              (300)               --        
  Issuance of common stock in a public offering,            68,166                --                --                --        
    net of issuance costs of $4,239
  Issuance of common stock in a private placement            1,058                --                --                --        
  Issuance of common stock under employee stock                469                --                --                --        
    purchase plans
  Exercise of stock options and warrants                     1,397                --                --                --        
  Translation adjustment                                        --                --               (62)               --        
  Realized gain on investments                                  --                --                --                --        
  Unrealized market loss on investments                         --                --                --                --        
  Tax benefit related to stock options                       2,107                --                --                --        
  Net loss                                                      --           (15,185)               --                --        
                                                        ----------        ----------        ----------        ----------        
BALANCE, JUNE 30, 1996                                     109,857           (11,094)             (362)               --        
  Issuance of common stock in an immaterial                    165               527                --                --        
    pooling
  Issuance of common stock in the purchase of                5,892                --                --                --        
    businesses
  Issuance of common stock under employee stock              3,549                --                --                --        
    purchase plans
  Exercise of stock options and warrants                     4,152                --                --                --        
  Translation adjustment                                        --                --               107                --        
  Issuance of treasury stock to charity                         --                --                --                --        
  Unrealized market loss on investments                         --                --                --                --        
  Tax benefit related to stock options                       3,963                --                --                --        
  Net income                                                    --            13,155                --                --        
                                                        ----------        ----------        ----------        ----------        
BALANCE, JUNE 30, 1997                                  $  127,578        $    2,588        $     (255)       $       --        
                                                        ==========        ==========        ==========        ==========        
</TABLE>

<TABLE>
<CAPTION>
                                                              TREASURY STOCK                UNREALIZED          TOTAL
                                                          NUMBER                               GAIN          STOCKHOLDERS'
                                                         OF SHARES          AMOUNT          (LOSS) ON            EQUITY
                                                                                           INVESTMENTS    
                                                                                            
<S>                                                      <C>              <C>              <C>               <C>       
BALANCE, JUNE 30, 1994                                     229,188        $     (497)       $       --        $   17,156
  Issuance of common stock in public offerings,                 --                --                --            17,849
    net of issuance costs of $1,223
  Issuance of common stock under employee stock                 --                --                --               245
    purchase plans
  Exercise of stock options and warrants                        --                --                --             1,182
  Liquidation of fractional shares                              64                --                --                --
  Conversion of preferred stock to common stock                 --                --                --                --
  Purchase of treasury stock                                 1,144                (5)               --                (5)
  Repayment of receivable                                       --                --                --                15
  Translation adjustment                                        --                --                --                90
  Unrealized market gain on investments                         --                --               282               282
  Tax benefit related to stock options                          --                --                --               486
  Dividend distributions to stockholders relating               --                --                --              (927)
    to acquired Subchapter S corporation, net
  Net income                                                    --                --                --             5,416
                                                        ----------        ----------        ----------        ----------
BALANCE, JUNE 30, 1995                                     230,396              (502)              282            41,789
  Issuance of common stock in a public offering,                --                --                --            68,457
    net of issuance costs of $4,239
  Issuance of common stock in a private placement               --                --                --             1,064
  Issuance of common stock under employee stock                 --                --                --               474
    purchase plans
  Exercise of stock options and warrants                        --                --                --             1,475
  Translation adjustment                                        --                --                --               (62)
  Realized gain on investments                                  --                --              (282)             (282)
  Unrealized market loss on investments                         --                --                (2)               (2)
  Tax benefit related to stock options                          --                --                --             2,107
  Net loss                                                      --                --                --           (15,185)
                                                        ----------        ----------        ----------        ----------
BALANCE, JUNE 30, 1996                                     230,396              (502)               (2)           99,835
  Issuance of common stock in an immaterial                     --                --                --               702
    pooling
  Issuance of common stock in the purchase of                   --                --                --             5,908
    businesses
  Issuance of common stock under employee stock                 --                --                --             3,570
    purchase plans
  Exercise of stock options and warrants                        --                --                               4,203
  Translation adjustment                                        --                --                --               107
  Issuance of treasury stock to charity                        (66)               --                --                --
  Unrealized market loss on investments                         --                --                (2)               (2)
  Tax benefit related to stock options                          --                --                --             3,963
  Net income                                                    --                --                --            13,155
                                                        ----------        ----------        ----------        ----------
BALANCE, JUNE 30, 1997                                     230,330        $     (502)       $       (4)       $  131,441
                                                        ==========        ==========        ==========        ==========
</TABLE>

  The accompanying notes are an integral part of these consolidated financial
                                  statements.

                                      F-5
<PAGE>   37
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES

                      CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)

<TABLE>
<CAPTION>
                                                                         YEARS ENDED JUNE 30,
                                                                    1995         1996         1997
<S>                                                              <C>          <C>          <C>     
CASH FLOWS FROM OPERATING ACTIVITIES:
  Net income (loss)                                              $  5,416     $(15,185)    $ 13,155
  Adjustments to reconcile net income (loss) to net
  cash provided by operating activities -
    Depreciation and amortization                                   2,748        5,641       11,301
    Charge for in-process research and development                     --       24,421        8,664
    Deferred income taxes                                           2,573         (295)      (1,646)
    Changes in assets and liabilities -
      Accounts receivable                                          (3,061)     (12,415)      (9,501)
      Prepaid expenses and other current assets                      (780)       1,053       (4,042)
      Long-term installments receivable                            (8,503)       1,790      (20,251)
      Accounts payable and accrued expenses                         2,446        7,000        3,750
      Unearned revenue                                                 66        2,823       (7,835)
      Deferred revenue                                              2,716        3,560        7,229
                                                                 --------     --------     --------
           Net cash provided by operating activities                3,621       18,393          824
                                                                 --------     --------     --------
CASH FLOWS FROM INVESTING ACTIVITIES:
  Purchase of property and leasehold improvements                  (2,565)      (7,017)     (18,093)
  Increase in computer software development costs                  (1,026)        (908)      (2,384)
  (Increase) decrease in other assets                                (154)         117         (549)
  (Increase) decrease in short-term investments                   (18,364)     (20,197)      22,715
  Increase (decrease) in other liabilities                            401          955         (815)
  Cash acquired in an immaterial pooling                               --           --          792
  Cash used in the purchase of business, net of cash acquired          --      (44,723)      (6,232)
                                                                 --------     --------     --------
           Net cash used in investing activities                  (21,708)     (71,773)      (4,566)
                                                                 --------     --------     --------
CASH FLOWS FROM FINANCING ACTIVITIES:
  Issuance of common stock                                         17,849       69,521           --
  Issuance of common stock under employee stock                       245          474        3,570
    purchase plans
  Exercise of common stock options and warrants                     1,182          925        4,203
  Purchase of treasury shares                                          (5)          --           --
  Repayment of notes receivable for stock issued                       15           --           --
  Proceeds from subordinated note payable to related party          2,000           --           --
  Payment of subordinated notes payable to related parties             --       (3,450)          --
  Payments of long-term debt and capital lease obligations           (661)      (5,693)        (571)
  Dividend distributions to stockholders relating to
    acquired Subchapter S corporation, net                           (927)          --           --
                                                                 --------     --------     --------
           Net cash provided by financing activities               19,698       61,777        7,202
                                                                 --------     --------     --------
EFFECT OF EXCHANGE RATE CHANGES ON CASH                                90          (62)         107
                                                                 --------     --------     --------
INCREASE IN CASH AND CASH EQUIVALENTS                               1,701        8,335        3,567

CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR                        2,488        4,189       12,524
                                                                 --------     --------     --------
CASH AND CASH EQUIVALENTS, END OF YEAR                           $  4,189     $ 12,524     $ 16,091
                                                                 ========     ========     ========
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
  Cash paid for income taxes                                     $    600     $  1,861     $  2,334
                                                                 ========     ========     ========
  Cash paid for interest                                         $    524     $  1,363     $    199
                                                                 ========     ========     ========
SUPPLEMENTAL SCHEDULE OF NONCASH INVESTING AND
FINANCING ACTIVITIES:
  Increase in equipment under capital lease obligations          $     --     $    105           --
                                                                 ========     ========     ========
  Increase in additional paid-in capital and                     $    486     $  2,107     $  3,963
    decrease in accrued expenses relating to the tax             =========    =========    =========
    benefit of exercise of nonqualified stock options

  Increase in common stock and additional paid-in                $     --     $    550     $     --
    capital and decrease in subordinated notes                   =========    =========    =========
    payable to a related party relating to the
    exercise of warrants

SUPPLEMENTAL DISCLOSURE OF CASH FLOWS RELATED TO
ACQUISITIONS:
  During 1996 and 1997, the Company acquired certain
  companies as described in Note 3.  These
  acquisitions are summarized as follows -
    Fair value of assets acquired, excluding cash                $     --     $ 47,919     $ 15,469
    Issuance of common stock related to acquisitions                   --           --       (5,908)
    Payments in connection with the acquisitions,                      --      (44,723)      (6,232)
      net of cash acquired                                       --------     --------     --------           
           Liabilities assumed                                   $     --     $  3,196     $  3,329
                                                                 ========     ========     ========
</TABLE>

  In May 1995, the Company acquired Industrial Systems, Inc., which was
  accounted for as a pooling-of-interests. In September 1996, the Company
  acquired B-JAC International, Inc., which was accounted for as a
  pooling-of-interests.

  The accompanying notes are an integral part of these consolidated financial
                                  statements.


                                       F-6
<PAGE>   38


                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997




(1)  OPERATIONS

     Aspen Technology, Inc. (the Company) develops and markets process modeling
     and automation software and services internationally to the process
     industries. The Company's principal products are used to analyze, design
     and automate the manufacturing processes in the chemicals, petroleum,
     pharmaceuticals, pulp and paper, electric power, and food and consumer
     products industries. The Company's services include hot line assistance,
     training courses and design and implementation consulting services on a
     contract basis.

(2)  SIGNIFICANT ACCOUNTING POLICIES

     (a) Principles of Consolidation

         The accompanying consolidated financial statements include the results
         of operations of the Company and its wholly owned subsidiaries. All
         material intercompany balances and transactions have been eliminated in
         consolidation.

     (b) Cash and Cash Equivalents

         Cash and cash equivalents are stated at cost, which approximates
         market, and consist of short-term, highly liquid investments with
         original maturities of less than three months.

     (c) Short-Term Investments

         The Company accounts for short-term investments in accordance with
         Statement of Financial Accounting Standards (SFAS) No. 115, Accounting
         for Certain Investments in Debt and Equity Securities. Under SFAS No.
         115, securities purchased to be held for indefinite periods of time,
         and not intended at the time of purchase to be held until maturity, are
         classified as available-for-sale securities. Securities classified as
         available-for-sale are required to be recorded at market value in the
         financial statements. Unrealized gains and losses have been accounted
         for as a separate




                                       F-7
<PAGE>   39
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


         component of stockholders' equity. Available-for-sale investments as of
         June 30, 1996 and 1997 are as follows (in thousands):

<TABLE>
<CAPTION>
                                            CONTRACTED       MARKET VALUE AT JUNE 30,
                DESCRIPTION                  MATURITY           1996        1997
                                                               

<S>                                        <C>               <C>          <C>
          Commercial paper                 1 - 11  months    $  38,559    $   2,150
                                    
          Corporate and foreign bonds      1 - 12  months            -        3,030
                               
          Corporate and foreign bonds        1-5 years               -       10,663
                                                             ---------    ---------
                                                               $38,559    $  15,843
                                                             =========    =========
</TABLE>


         The Company had no realized gains or losses for the years ended June
         30, 1995 and 1997 and had realized gains of $282,000 for the year ended
         June 30, 1996.

     (d) Depreciation and Amortization

         The Company provides for depreciation and amortization, computed using
         the straight-line and declining balance methods, by charges to
         operations in amounts estimated to allocate the cost of the assets over
         their estimated useful lives, as follows:

                                               ESTIMATED
                 ASSET CLASSIFICATION         USEFUL LIFE

          Building and improvements           7 - 30 years
          Computer equipment                  3 - 10 years
          Purchased software                      3 years
          Furniture and fixtures              3 - 10 years
          Leasehold improvements              Life of lease

     (e) Land

         In connection with the acquisition of Setpoint, Inc. (see Note 3(b)),
         the Company acquired land that is being held for investment purposes.
         The land was recorded at its appraised value at the date of
         acquisition.

     (f) Revenue Recognition

         The Company recognizes revenue from software licenses upon the shipment
         of its products, pursuant to a signed noncancelable license agreement.
         In the case of license renewals, revenue is recognized upon execution
         of the renewal license agreement. The Company has no other significant
         vendor obligations or collectibility risk associated with its product
         sales. The Company recognizes revenue from postcontract customer
         support ratably over the period of the 




                                       F-8
<PAGE>   40
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)

         postcontract arrangement. The Company accounts for insignificant vendor
         obligations by deferring a portion of the revenue and recognizing it
         either ratably as the obligations are fulfilled or when the related
         services are performed. If significant application development services
         are performed in connection with the purchase of a license, the license
         fees are recognized as the application development services are
         performed.

         Service revenues from fixed-price contracts are recognized using the
         percentage-of-completion method, measured by the percentage of costs
         (primarily labor) incurred to date as compared to the estimated total
         costs (primarily labor) for each contract. When a loss is anticipated
         on a contract, the full amount thereof is provided currently. Service
         revenues from time and expense contracts and consulting and training
         revenue are recognized as the related services are performed. Services
         that have been performed but for which billings have not been made are
         recorded as unbilled services, and billings that have been recorded
         before the services have been performed are recorded as unearned
         revenue in the accompanying consolidated balance sheets.

         Installments receivable represent the present value of future payments
         related to the financing of noncancelable term license agreements that
         provide for payment in installments over a one- to five-year period. A
         portion of each installment agreement is recognized as interest income
         in the accompanying consolidated statements of operations. The interest
         rates in effect in fiscal 1995, 1996 and 1997 were 11% to 12%, 11% to
         12% and 8.5% to 11%, respectively.

     (g) Computer Software Development Costs

         In compliance with SFAS No. 86, Accounting for the Costs of Computer
         Software To Be Sold, Leased or Otherwise Marketed, certain computer
         software development costs are capitalized in the accompanying
         consolidated balance sheets. Capitalization of computer software
         development costs begins upon the establishment of technological
         feasibility. Amortization of capitalized computer software development
         costs are provided on a product-by-product basis using the
         straight-line method over the remaining estimated economic life of the
         product, not to exceed three years. Total amortization expense charged
         to operations was approximately $630,000, $735,000 and $1,143,000 in
         fiscal 1995, 1996 and 1997, respectively.

     (h) Foreign Currency Translation

         The financial statements of the Company's foreign subsidiaries are
         translated in accordance with SFAS No. 52, Foreign Currency
         Translation. The determination of functional currency is based on the
         subsidiaries' relative financial and operational independence from the
         Company. Foreign currency exchange and translation gains or losses for
         certain wholly owned subsidiaries are credited or charged to the
         accompanying consolidated statements of operations since the functional
         currency of the subsidiaries is the U.S. dollar. Gains and losses from
         foreign currency translation related to entities whose functional
         currency is their local currency are credited or 





                                      F-9
<PAGE>   41
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)

         charged to the cumulative translation adjustment account, included in
         stockholders' equity in the accompanying consolidated balance sheets.

         At June 30, 1996 and 1997, the Company had long-term installments
         receivable of approximately $7,301,000 and $8,987,000 denominated in
         foreign currencies. The June 1997 installments receivable mature
         through January 2001 and have been hedged with specific foreign
         currency contracts. The Company records a foreign currency gain or loss
         at the time the Company enters into the foreign currency contract.
         There have been no material gains or losses recorded relating to hedge
         contracts for the periods presented.

     (i) Net Income (Loss) per Share

         Net income (loss) per common and common equivalent share is computed
         using the weighted average number of common and dilutive common
         equivalent shares outstanding during each period, assuming conversion
         of all classes of convertible preferred stock into common stock. Shares
         of stock issuable pursuant to stock options and warrants have been
         included, using the treasury stock method, where their effect is
         dilutive.

         In March 1997, the Financial Accounting Standards Board (FASB) issued
         SFAS No. 128, Earnings per Share. SFAS No. 128 establishes standards
         for computing and presenting earnings per share and applies to entities
         with publicly traded common stock or potential common stock. This
         statement is effective for fiscal years ending after December 15, 1997,
         and early adoption is not permitted. When adopted, the statement will
         require restatement of prior years' earnings per share. The Company
         will adopt this statement for its fiscal year ending June 30, 1998.



                                      F-10
<PAGE>   42
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


         Pro forma calculations of basic and diluted earning per share, as
         required by SFAS No. 128, are as follows (in thousands, except per 
         share data):

<TABLE>
<CAPTION>
                                    1995        1996         1997

<S>                               <C>         <C>           <C>        
          Net income (loss)       $   5,416   $ (15,185)    $  13,155  
                                  =========   =========     =========  
                                                                       
          Basic weighted average     13,770      15,857        19,628  
          shares outstanding                                           
                                                                       
          Weighted average                                             
          common equivalent    
          shares                      1,792           -         1,339  
                                  ---------   ---------     ---------  
                                                                 
                                                                       
          Diluted weighted                                             
          outstanding                                                 
          average shares             15,562      15,857        20,967
                                  =========   =========     =========
          Basic earnings per      $    0.39   $   (0.96)    $    0.67
          share
                                                                       
          Diluted earnings per    $    0.35   $   (0.96)    $    0.63  
          share                                             
</TABLE>


     (j) Management Estimates

         The preparation of financial statements in conformity with generally
         accepted accounting principles requires management to make estimates
         and assumptions. These estimates and assumptions affect the reported
         amounts of assets and liabilities and disclosure of contingent assets
         and liabilities at the date of the financial statements and the
         reported amounts of revenues and expenses during the reporting period.
         Actual results could differ from those estimates.



                                       F-11
<PAGE>   43
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)
                             

     (k) Concentration of Credit Risk

         SFAS No. 105, Disclosure of Information About Financial Instruments
         with Off-Balance-Sheet Risk and Financial Instruments with
         Concentrations of Credit Risk, requires disclosure of any significant
         off-balance-sheet and credit risk concentrations. Financial instruments
         that potentially subject the Company to concentrations of credit risk
         are principally cash and cash equivalents, investments, accounts
         receivable and installments receivable. The Company places its cash and
         cash equivalents and investments in highly rated institutions.
         Concentration of credit risk with respect to receivables is limited to
         certain customers (end users and distributors) to which the Company
         makes substantial sales. To reduce risk, the Company routinely assesses
         the financial strength of its customers, hedges specific foreign
         receivables and routinely sells its receivables to financial
         institutions with and without recourse. As a result, the Company
         believes that its accounts and installments receivable credit risk
         exposure is limited. The Company maintains an allowance for potential
         credit losses but historically has not experienced any significant
         losses related to individual customers or groups of customers in any
         particular industry or geographic area.

     (l) Financial Instruments

         SFAS No. 107, Disclosures About Fair Value of Financial Instruments,
         requires disclosure about fair value of financial instruments.
         Financial instruments consist of cash and cash equivalents, short-term
         investments, accounts receivable and installments receivable. The
         estimated fair value of these financial instruments approximates their
         carrying value and, except for accounts receivable and installments
         receivable, is based primarily on market quotes.

     (m) Intangible Assets

         Intangible assets consist of goodwill, existing products, trade names
         and assembled work force of certain acquired entities. Intangible
         assets are being amortized on a straight-line basis over estimated
         useful lives of five to twelve years. At each balance sheet date, the
         Company evaluates the realizability of intangible assets based on
         profitability and cash flow expectations for the related asset or
         subsidiary. Based on its most recent analysis, the Company believes
         that no impairment of intangible assets exists at June 30, 1997.
         Goodwill (net of accumulated amortization) was approximately $5,003,000
         at June 30, 1997. Amortization of goodwill amounted to approximately
         $40,000 and $279,000 for the years ended June 30, 1996 and 1997,
         respectively.




                                       F-12
<PAGE>   44
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)

(3)  ACQUISITIONS

     (a) Dynamic Matrix Control Corporation (DMCC)

         On January 5, 1996, the Company acquired 80.7% of the outstanding
         shares of common stock of DMCC, and on February 8, 1996, the Company
         acquired the remaining 19.3% of DMCC common stock, for an aggregate
         purchase price of $20,139,000 in cash and the assumption of certain
         expenses related to the acquisition. DMCC is a supplier of on-line
         automation and information management software and services to
         companies in process manufacturing industries.

         For financial statement purposes, this acquisition was accounted for as
         a purchase, and accordingly, the results of operations of DMCC from
         January 5, 1996 forward are included in the Company's consolidated
         statements of operations. The fair market value of assets acquired and
         liabilities assumed was based on an independent appraisal. The portion
         of the purchase price allocated to in-process research and development
         represents projects that had not yet reached technological feasibility
         and had no alternative future uses as of January 5, 1996. The purchase
         price was allocated to the fair value of assets acquired and
         liabilities assumed as follows (in thousands):

<TABLE>
<CAPTION>
                         DESCRIPTION                  AMOUNT           LIFE

<S>                                                   <C>         <C>                
          Purchased in-process research and           $  9,521           -
            development
          Existing technology                            1,740       5 years
          Other intangibles                              1,066    5 - 10 years
          Building                                         627      30 years
          Uncompleted contracts                            596    Life of contracts
                                                    ----------
                                                        13,550

          Net book value of tangible assets
          acquired, less liabilities assumed             8,080
                                                    ----------
                                                        21,630

          Less -- Deferred taxes                         1,491
                                                    ----------

                                                      $ 20,139
                                                    ==========
</TABLE>


         For tax purposes, this acquisition was accounted for as a purchase of
         stock, and due to the different basis in assets for book and tax
         purposes, deferred taxes were provided for as part of the purchase
         allocation in accordance with SFAS No. 109.




                                       F-13
<PAGE>   45
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


     (b) Setpoint, Inc. (Setpoint)

         On February 9, 1996, the Company acquired all of the outstanding shares
         of Setpoint for an aggregate purchase price of $27,780,000, after final
         adjustment, in cash and the assumption of certain expenses related to
         the acquisition. The purchase price was subject to certain downward
         adjustments based on the net worth of Setpoint as of December 31, 1995.
         In May 1996, this contingency was resolved, resulting in a $400,000
         reduction of purchase price. Setpoint supplies on-line automation and
         information management software and services to companies in process
         manufacturing industries.

         For financial statement purposes, this acquisition was accounted for as
         a purchase, and accordingly, the results of operations of Setpoint from
         February 9, 1996 forward are included in the Company's consolidated
         statements of operations. The fair market value of assets acquired and
         liabilities assumed was based on an independent appraisal. The portion
         of the purchase price allocated to in-process research and development
         represents projects that had not yet reached technological feasibility
         and had no alternative future use as of February 9, 1996. The purchase
         price was allocated to the fair value of assets acquired and
         liabilities assumed as follows (in thousands):

<TABLE>
<CAPTION>
                      DESCRIPTION               AMOUNT           LIFE          
                                                                               
<S>                                             <C>          <C>                            
          Purchased in-process research and     $ 14,900              -        
            development                                                        
          Existing technology                      3,308        5 years        
          Intangible assets                        3,127     5 - 10 years      
          Uncompleted contracts                      504     Life of contracts 
                                              ----------     
                                                  21,839

          Net book value of tangible assets
          acquired, less liabilities assumed       7,984
                                                  29,823

          Less -- Deferred taxes                   2,043
                                              ----------

                                                $ 27,780
                                              ==========
</TABLE>

         For tax purposes, this acquisition was accounted for as a purchase of
         stock, and due to the different basis in assets for book and tax
         purposes, deferred taxes were provided for as part of the purchase
         allocation in accordance with SFAS No. 109.



                                      F-14
<PAGE>   46
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)



     (c) B-JAC International, Inc. (B-JAC)

         On October 1, 1996, the Company acquired 100% of the outstanding shares
         of common stock of B-JAC, a major supplier of detailed heat exchanger
         modeling software. The Company exchanged 104,162 shares of its common
         stock valued at $3.4 million for all outstanding shares of B-JAC common
         stock. The acquisition has been accounted for as a
         pooling-of-interests. This transaction is immaterial to the Company's
         financial position and results of operations and, accordingly, the
         historical financial statements have not been restated.

     (d) Process Control Division of Cambridge Control Limited

         On October 7, 1996, the Company acquired the process control division
         of Cambridge Control Limited (the Cambridge Control Division) for $1.9
         million, including $300,000 in related costs. The Cambridge Control
         Division specializes in advanced process control solutions,
         specifically aimed toward process manufacturing controls applications
         for the refining, petrochemical and pulp and paper industries.

         For financial statement purposes, this acquisition was accounted for as
         a purchase, and accordingly, the results of operations of the process
         control division from October 7, 1996 forward are included in the
         Company's consolidated statements of operations. The fair market value
         of assets acquired and liabilities assumed was based on an independent
         appraisal. The portion of the purchase price allocated to in-process
         research and development represents projects that had not yet reached
         technological feasibility and had no alternative future use as of
         October 7, 1996. The purchase price was allocated to the fair value of
         assets acquired and liabilities assumed as follows (in thousands):

<TABLE>
<CAPTION>
                      DESCRIPTION               AMOUNT            LIFE

<S>                                             <C>           <C>                    
          Purchased in-process research and     $    764               -
            development
          Existing technology                        100         5 years
          Intangible assets                        1,437      5-10 years
                                                --------
                                                   2,301

          Net book value of tangible assets
          acquired, less liabilities assumed        (411)
                                                --------
                                                $  1,890
                                                ========
</TABLE>

         For tax purposes, this acquisition was accounted for as a purchase of
         assets; accordingly, the basis in assets and liabilities for book and
         tax purposes are primarily the same.




                                      F-15
<PAGE>   47
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


     (e) Bechtel Corporation PIMS (Process Industries Modeling System) and Basil
         Joffe Associates, Inc.

         On December 31, 1996, the Company acquired the assets of Bechtel's PIMS
         (Process Industries Modeling System) division for approximately $4.3
         million in cash and an additional $2.2 million in assumed liabilities
         and acquisition-related costs. On the same date, the Company acquired
         all the outstanding shares of the related software development
         organization, Basil Joffee Associates, Inc., for approximately 156,000
         shares of its common stock valued at approximately $5,900,000. The
         proprietary PIMS software developed and sold by these businesses is
         used by companies in process industries for economic planning and
         scheduling based on large linear programming models.

         For financial statement purposes, these acquisitions have been
         accounted for as purchases, and accordingly, the results of operations
         of Bechtel Corporation PIMS and Basil Joffe Associates, Inc. from
         December 31, 1996 forward are included in the Company's consolidated
         statements of operations. The fair market value of assets acquired and
         liabilities assumed was based on an independent appraisal. The portion
         of the purchase price allocated to in-process research and development
         represents projects that had not yet reached technological feasibility
         and had no alternative future use as of December 31, 1996. The purchase
         price was allocated to the fair value of assets acquired and
         liabilities assumed as follows (in thousands):

<TABLE>
<CAPTION>
                      DESCRIPTION               AMOUNT            LIFE

<S>                                           <C>             <C>                   
          Purchased in-process research and     $  7,900             -
            development
          Existing technology                        500        5 years
          Intangible assets                        4,093      7 - 12 years
                                              ----------
                                                  12,493

          Net book value of tangible assets
          acquired, less liabilities assumed      (2,018)
                                              ----------
                                                  10,475

          Less -- Deferred taxes                     148
                                              ----------

                                                $ 10,327
                                              ==========
</TABLE>


         For tax purposes, the acquisition of Process Industries Modeling System
         is being accounted for as a purchase of assets and the acquisition of
         Basil Joffe Associates is being accounted for as a purchase of stock.
         Due to the different basis in assets and liabilities for book and tax
         purposes, deferred taxes have been provided for as part of the purchase
         allocation in accordance with SFAS No. 109.



                                      F-16
<PAGE>   48
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


     (f) Unaudited Pro Forma Combined Results

         The following table represents selected unaudited pro forma combined
         financial information for the Company, DMCC and Setpoint, assuming the
         companies had combined at the beginning of fiscal 1996 (in thousands,
         except per share data):

<TABLE>
<CAPTION>
                                              YEAR ENDED     YEAR ENDED
                                               JUNE 30,       JUNE 30,
                                                 1995          1996(1)

<S>                                            <C>            <C>      
          Pro forma revenue                    $ 114,730      $ 142,668
          Pro forma net income                 $   4,243      $   8,599
          Pro forma net income per common
            and common equivalent share        $    0.27      $    0.50
          Pro forma weighted average common
            and common equivalent shares          15,562         17,298
            outstanding
</TABLE>


                (1)   Does not reflect the charge for in-process research and 
                      development and nonrecurring acquisition charges.

         The pro forma effect of the acquisition of B-JAC, the Cambridge Control
         Division, Bechtel Corporation PIMS and Basil Joffe Associates, Inc. has
         not been presented, as it is immaterial.

         Pro forma results are not necessarily indicative of either actual
         results of operations that would have occurred had the acquisitions
         been made at the beginning of fiscal 1995 or of future results.

     (g)     Acquisitions Subsequent to Year End

         On August 27, 1997 and August 28, 1997, the Company acquired 100% of
         the outstanding shares of NeuralWare, Inc. (NeuralWare) and The SAST
         Corporation Limited (SAST) respectively. SAST is a provider of dynamic
         simulation and operator training services and applications, and
         NeuralWare is a provider of neural network and related technologies.

         The Company completed these acquisitions primarily through the exchange
         of 314,000 shares of its common stock valued at approximately
         $12,000,000 for all the outstanding shares of both entities. These
         acquisitions will be accounted for as poolings-of-interests. As the
         transactions are immaterial to the Company's financial position and
         results of operations historical financial statements will not be
         restated.




                                       F-17
<PAGE>   49
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)



(4)  LINE OF CREDIT

     The Company has a revolving line-of-credit agreement with a bank, which
     provides for borrowings up to $30,000,000, subject to existing limitations.
     The commitment fee for the unused portion of the revolving line of credit
     ranges from .25% to .50%, based on the financial position of the Company,
     as defined, and is payable quarterly. At the Company's election, borrowings
     bear interest on the basis of the applicable LIBOR, as defined (5.69% as of
     June 30, 1997), or at the bank's prime rate (8.5% as of June 30, 1997). The
     line is subject to certain covenants, including profitability and operating
     ratios, as defined. As of June 30, 1997, the Company had an available
     borrowing base of approximately $30,000,000, of which approximately
     $744,000 was reserved for certain performance bonds relating to service
     contracts. The line of credit expires on December 31, 1998.

(5)  NOTE PAYABLE

     In connection with the acquisition of Setpoint in February 1996, the
     Company assumed approximately $5,200,000 of intercompany debt payable to
     the former parent of Setpoint. Upon the closing of the acquisition, the
     Company paid approximately $1,700,000 of this debt and signed a note for
     the remaining balance of $3,500,000. The note accrued interest at a rate of
     6% per year. This obligation was repaid on June 27, 1996.

(6)  CAPITAL LEASE OBLIGATIONS

     The Company has numerous capital lease arrangements. These obligations
     accrue interest at rates ranging from 8.5% to 17.0% and are payable in
     various monthly installments of principal and interest ranging from $149 to
     $11,696, expiring on various dates through November 2002.

     Maturities are as follows (in thousands):

<TABLE>
<CAPTION>
                                                      AMOUNT
<S>                                                   <C>
     Years Ending June 30,
     1998                                              $364
     1999                                               196
     2000                                               130
     2001                                               131
     2002                                                54
                                                       ----
                                                       $875

Less -- Amount representing interest                    125
     -- Current maturities                              288
                                                       ----
                                                       $462
                                                       ====
</TABLE>


                                      F-18
<PAGE>   50
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


(7)  SUBORDINATED NOTES PAYABLE TO A RELATED PARTY

     At June 30, 1995, the Company had $4,000,000 outstanding on subordinated
     notes payable to an outside investor, of which a director of the Company is
     an officer. The notes were repayable $2,000,000 on April 30, 1997 and
     $2,000,000 on April 30, 1998, with interest at 9.6%, payable quarterly.

     In December 1995 and June 1996, the lender exercised 77,500 and 60,000 of
     warrants, respectively. The total proceeds due to the Company relating to
     the exercise of the warrants of $550,000 were recognized as a reduction of
     principal on the notes. The Company paid the remaining balance of
     $3,450,000 on June 27, 1996.

(8)  PREFERRED STOCK

     The Company's Board of Directors is authorized, subject to any limitations
     prescribed by law, without further stockholder approval, to issue, from
     time to time, up to an aggregate of 10,000,000 shares of preferred stock in
     one or more series. Each such series of preferred stock shall have such
     number of shares, designations, preferences, voting powers, qualifications
     and special or relative rights or privileges, which may include, among
     others, dividend rights, voting rights, redemption and sinking fund
     provisions, liquidation preferences and conversion rights, as shall be
     determined by the Board of Directors in a resolution or resolutions
     providing for the issuance of such series. Any such series of preferred
     stock, if so determined by the Board of Directors, may have full voting
     rights with the common stock or superior or limited voting rights and may
     be convertible into common stock or another security of the Company.

(9)  COMMON STOCK

     (a) Authorized and Outstanding Shares

         On November 11, 1996, the Company increased its authorized shares of
         $.10 par value common stock from 30,000,000 to 40,000,000. On February
         14, 1997, the Company effected a two for one stock split through the
         issuance of a stock dividend. All share and per share amounts affected
         by this split have been retroactively adjusted for all periods
         presented.

     (b) Warrants

         During fiscal 1990, the Company issued warrants to purchase 255,000
         shares of common stock to the holder of the subordinated notes payable
         to a related party (see Note 7). In February 1995, warrants to purchase
         100,000 shares were exercised and sold as part of the Company's second
         public offering of stock. The remaining warrants to purchase 155,000
         shares of common stock 



                                      F-19
<PAGE>   51
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)

         were exercised in December 1995. During 1991, the Company issued an
         additional warrant to purchase 120,000 shares of common stock to the
         holder of the subordinated notes payable (see Note 7). These warrants
         were exercised in June 1996.

         During fiscal 1992, the Company issued warrants to purchase 60,000
         shares of common stock to a research consultant at an exercise price of
         $3.34 per share. In February 1995, warrants to purchase 27,000 shares
         were exercised and sold as part of the Company's offering of common
         stock. In 1996, warrants to purchase 1,150 shares were exercised. In
         1997, warrants to purchase 5,700 shares were exercised and warrants to
         purchase 774 shares were terminated. The remaining warrants to purchase
         25,376 shares of common stock are exercisable through June 30, 2001.

         During fiscal 1993, the Company issued warrants to purchase 12,000
         shares of common stock to two research consultants at an exercise price
         of $2.67 per share. In 1997, warrants to purchase 2,250 shares were
         exercised. The remaining warrants to purchase 9,750 shares of common
         stock are currently exercisable and expire June 10, 1998.

     (c) Stock Options

         In July 1987 and August 1988, the Company entered into stock option
         agreements covering 120,000 shares of common stock. The purchase price
         under the options is $0.93 to $1.05 based on the fair market value of
         the common stock on the date of grant. In fiscal 1995, options covering
         90,000 shares of common stock at $1.05 per share were exercised. During
         fiscal 1997, options covering the remaining 30,000 shares of common
         stock at an exercise price of $0.93 were exercised.

         Prior to November 1995, options were granted under the 1988
         Nonqualified Stock Option Plan (the 1988 Plan), which provided for the
         issuance of nonqualified stock options. In November 1995, the Board of
         Directors approved the establishment of the 1995 Stock Option Plan (the
         1995 Plan) and the 1995 Directors Stock Option Plan (the 1995 Directors
         Plan), which provided for the issuance of incentive stock options and
         nonqualified options. Under these plans, the Board of Directors may
         grant stock options to purchase up to an aggregate of 3,827,687 (as
         adjusted) shares of common stock. Shares available for grant under
         these plans were increased on July 1, 1996 and 1997 by an amount equal
         to 5% of the outstanding shares as of the preceding June 30. As a
         result of the adoption of the 1995 Plan, no additional options may be
         granted pursuant to the 1988 Plan. In December 1996, the shareholders
         of the Company approved the establishment of the 1996 Special Stock
         Option Plan (the 1996 Plan). This plan provides for the issuance of
         incentive stock options and nonqualified options to purchase up to
         500,000 shares of common stock. The exercise price of options are
         granted at a price not less than 100% of the fair market value of the
         common stock on the date of grant. Stock options become exercisable
         over varying periods and expire no later than 10 years from the date of
         grant.



                                      F-20
<PAGE>   52
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)

         The following is a summary of stock option activity under the 1988
         Plan, the 1995 Plan, the 1995 Directors Plan and the 1996 Plan:

<TABLE>
<CAPTION>
                                           NUMBER OF          WEIGHTED
                                            OPTIONS            AVERAGE
                                                           EXERCISE PRICE
                                                          
<S>                                      <C>               <C> 
          Outstanding, June 30, 1994       1,912,876          $   2.13
            Options granted                  270,000              8.45
            Options exercised               (357,368)             2.22
            Options terminated              (145,336)             2.16
                                          ----------       -----------
                                                          
          Outstanding, June 30, 1995       1,680,172              3.12
            Options granted                1,772,000             17.08
            Options exercised               (460,114)             1.90
            Options terminated               (51,300)            10.04
                                          ----------       -----------
                                                          
          Outstanding, June 30, 1996       2,940,758             11.65
            Options granted                  680,000             31.30
            Options exercised               (484,205)             8.21
            Options terminated              (157,616)            16.61
                                          ----------       -----------
                                                          
          Outstanding, June 30, 1997       2,978,937          $  16.44
                                          ==========          ========
</TABLE>

         As of June 30, 1997 there were 1,923,203 and 342,000 shares of common
         stock available for grant under the 1995 and 1996 plans, respectively.

         In connection with the 1995 acquisition of Industrial Systems, Inc.
         (ISI), the Company assumed the ISI option plan (the ISI Plan). Under
         this Plan, the Board of Directors of ISI were entitled to grant either
         incentive or nonqualified stock options for a maximum of 197,548 shares
         of common stock (as converted to reflect the pooling of interests and
         conversion to options to purchase Aspen common stock) to eligible
         employees, as defined.



                                       F-21
<PAGE>   53
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


         Activity under the ISI Plan is as follows:

<TABLE>
<CAPTION>
                                         NUMBER OF    WEIGHTED
                                          OPTIONS     AVERAGE
                                                      EXERCISE
                                                       PRICE

<S>                                     <C>         <C>   
          Outstanding, June 30, 1994      131,174      $  .45
            Exercised                    (105,094)        .38
                                        ---------   ---------

          Outstanding, June 30, 1995       26,080         .76
            Exercised                     (13,040)        .25
                                        ---------   ---------

          Outstanding, June 30, 1996       13,040        1.26
            Exercised                     (13,040)       1.26
                                        ---------   ---------

          Outstanding, June 30, 1997            -   $       -
                                        =========   =========

          Exercisable, June 30, 1997            -   $       -
                                        =========   =========
</TABLE>


         No future grants are available under this Plan.

         The following tables summarize information about stock options
         outstanding at June 30, 1997:


<TABLE>
<CAPTION>
              RANGE OF               OPTIONS         WEIGHTED         WEIGHTED
              EXERCISE             OUTSTANDING        AVERAGE          AVERAGE
               PRICES                AT JUNE         REMAINING        EXERCISE
                                    30, 1997        CONTRACTUAL         PRICE
                                                       LIFE         
                                                                    
<S>                                <C>              <C>             <C>     
            $    1.05                  228,660          1.9          $   1.05
             1.83 - 2.66               219,716          4.9              2.62
             3.33 - 4.00               260,564          6.9              3.41
            8.06 - 10.25               135,700          7.7              9.68
            13.12 - 19.12            1,369,295          8.5             16.48
            25.00 - 32.50              575,002          9.3             28.02
            38.00 - 40.18              190,000          9.5             38.36
                                   -----------                       --------
                                                                    
                                     2,978,937                       $  16.44
                                   ===========                       ========
</TABLE>
                                                               


                                      F-22
<PAGE>   54
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)





<TABLE>
<CAPTION>
                 RANGE OF                      OPTIONS               WEIGHTED
              EXERCISE PRICES                EXERCISABLE              AVERAGE
                                                                     EXERCISE
                                                                       PRICE
                                                                    
<S>                                          <C>                     <C>   
              $    1.05                        228,660                 $ 1.05
               1.83 - 2.66                     229,466                   2.63
               3.33 - 4.00                     171,302                   3.40
               8.50 - 10.25                     61,300                   9.86
              13.62 - 19.12                    363,403                  16.36
              25.00 - 32.50                     96,250                  27.42
                  38.00                          9,877                  38.00
                                             ---------              ---------
                                                                    
          Exercisable, June 30, 1997         1,160,258                 $ 9.47
                                             =========                 ======
                                                                  
                                                                    
          Exercisable, June 30, 1996           962,990                 $ 4.58
                                             =========                 ======
                                                                  
                                                                    
          Exercisable June 30, 1995          1,046,572                 $ 2.07
                                             =========                 ======
</TABLE>
                                                                  
                                                            
     (d) Fair Value of Stock Options               

         In October 1995, the FASB issued SFAS No. 123, Accounting for
         Stock-Based Compensation. SFAS No. 123 requires the measurement of the
         fair value of stock options to be included in the statement of income
         or disclosed in the notes to financial statements. The Company has
         determined that it will continue to account for stock-based
         compensation for employees under Accounting Principles Board Opinion
         No. 25, Accounting for Stock Issued to Employees, and elect the
         disclosure-only alternative under SFAS No. 123.

         Had compensation cost for the Company's option plan been determined
         based on the fair value at the grant dates, as prescribed in SFAS No.
         123, the Company's net income (in thousands) and net income per share
         would have been as follows:

<TABLE>
<CAPTION>
                                                     1996           1997
                                                            
<S>                                             <C>            <C>
          Net (loss) income (in thousands) -                          
              As reported                       $  (15,185)    $    13,155
              Pro forma                            (16,421)          8,474
                                                            
          Net (loss) income per share -                           
              As reported                       $    (0.96)    $      0.63
              Pro forma                              (1.16)           0.42
</TABLE>
                                                            


                                       F-23
<PAGE>   55
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


         The fair value of each option grant is estimated on the date of grant
         using the Black-Scholes option pricing model with the following
         assumptions used for grants during the applicable period: no dividend
         yield and volatility of 58% for all periods; risk-free interest rates
         of 5.54% to 6.83% for options granted during fiscal 1996 and 6.42% to
         6.76% for options granted during fiscal 1997; and a weighted average
         expected option term of 7.5 years for all periods. The weighted average
         fair value per share of options granted during 1996 and 1997 was $12.83
         and $23.49, respectively.

     (e) Employee Stock Purchase Plans

         In February 1986, the Company's Board of Directors approved the 1986
         Employees' Stock Purchase Plan, under which the Board of Directors
         could grant stock purchase rights for a maximum of 1,1400,000 shares
         through November 1995. In December 1995, the Company's Board of
         Directors approved the 1995 Employees' Stock Purchase Plan, under which
         the Board of Directors may grant stock purchase rights for a maximum of
         500,000 shares through November 2005.

         Participants are granted options to purchase shares of common stock on
         the last business day of each semiannual payment period for 85% of the
         market price of the common stock on the first or last business day of
         such payment period, whichever is less. The purchase price for such
         shares is paid through payroll deductions, and the current maximum
         allowable payroll deduction is 10% of each eligible employee's
         compensation. Under the plans, the Company issued 68,500 shares, 47,344
         shares and 78,570 shares during fiscal 1995, 1996 and 1997,
         respectively. As of June 30, 1997, 418,414 shares of common stock were
         available for future issuance under the 1995 Plan.

         In September 1992, the Company's Board of Directors approved the
         establishment of a UK Employees' Stock Purchase Arrangement for all
         eligible employees, as defined. Under this arrangement, the rights to
         purchase shares of the Company's common stock are granted at fair
         market value, as determined by the Board of Directors. The purchase
         price for these shares is paid through payroll deductions over a
         six-month period, and the employees are, in turn, paid a cash bonus
         equal to 15% of the stock price after applicable taxes are withheld.
         Under this arrangement, the Company issued 3,564 shares, 2,876 shares
         and 3,016 shares during fiscal 1995, 1996 and 1997, respectively.



                                       F-24
<PAGE>   56
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)




(10) INCOME TAXES

     The Company accounts for income taxes under the provisions of SFAS No. 109,
     Accounting for Income Taxes. Under the liability method specified by SFAS
     No. 109, a deferred tax asset or liability is measured based on the
     difference between the financial statement and tax bases of assets and
     liabilities, as measured by the enacted tax rates.

     The provisions for income taxes shown in the accompanying consolidated
     statements of operations are composed of the following (in thousands):

<TABLE>
<CAPTION>
                                   YEARS ENDED JUNE 30,     
                          1995             1996             1997
<S>                     <C>               <C>             <C> 
     Federal -                                         
       Current          $ 1,132           $4,512          $ 6,550
       Deferred           1,949             (295)           1,232
     State -                                           
       Current                -              892              901
       Deferred             485                -              224
     Foreign -                                         
       Current              159              505              692
                        -------           ------          -------
                                                       
                        $ 3,725           $5,614          $ 9,599
                        =======           ======          =======
</TABLE>
                                                       

     The provision for income taxes differs from the federal statutory rate due
     to the following:

<TABLE>
<CAPTION>
                                                   YEARS ENDED JUNE 30,
                                              1995        1996(1)     1997(1)
                                                                     
<S>                                         <C>          <C>          <C>  
     Federal tax at statutory rate            34.0%        35.0%        35.0%
     State income tax, net of federal          5.3          5.0          5.2
     tax benefit                                                     
     Foreign tax                              (4.1)         2.4         (1.8)
     Tax credits generated                    (2.5)        (8.2)        (4.2)
     Permanent differences, net                5.6          4.3          2.6
     Valuation allowance and other             2.5          (.7)         (.9)
                                            ------       ------       ------
           Provision for income taxes         40.8 %       37.8%        35.9%
                                            ======       ======       ======
</TABLE>


     (1)   Calculated based on pretax income, before nondeductible charges for
     in-process research and development, of $14,850,000 and $26,704,000 for
     1996 and 1997, respectively.



                                       F-25
<PAGE>   57
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


     The components of the net deferred tax liability recognized in the
     accompanying consolidated balance sheets are as follows (in thousands):

<TABLE>
<CAPTION>
                                           JUNE 30,
                                      1996           1997
                                                  
<S>                                  <C>            <C>    
     Deferred tax assets             $ 7,418        $ 6,260
     Deferred tax liabilities        (15,189)       (14,000)
                                   ---------      ---------                                                  
                                      (7,771)        (7,740)
                                                  
     Valuation allowance              (1,425)             -
                                   ---------      ---------
                                               
                                     $(9,196)       $(7,740)
                                   =========      =========                                                    
</TABLE>



     The approximate tax effect of each type of temporary difference and
     carryforwards are as follows (in thousands):

<TABLE>
<CAPTION>
                                           JUNE 30,
                                      1996           1997
                                                
<S>                                  <C>            <C>     
     Revenue related                 $(6,974)       $(7,665)
     Foreign operating losses          1,425          1,063
     Nondeductible reserves and        1,523          1,034
     accruals                                   
     Intangible assets                (3,819)        (2,241)
     Other temporary differences          74             69
                                    --------       --------
                                                
                                     $(7,771)       $(7,740)
                                    ========       ========         
</TABLE>


     The decrease in valuation allowance during 1997 resulted from the
     utilitization of previously reserved tax assets. The foreign operating loss
     carryforwards expire at various dates through 2011.



                                       F-26
<PAGE>   58
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)


(11) OPERATING LEASES

     The Company leases its facilities and various office equipment under
     noncancelable operating leases with terms in excess of one year. Rent
     expense charged to operations was approximately $2,227,000, $3,346,000 and
     $5,015,000 for the years ended June 30, 1995, 1996 and 1997, respectively.
     Future minimum lease payments under these leases as of June 30, 1997 are as
     follows (in thousands):

<TABLE>
<CAPTION>
                                   AMOUNT
<S>                              <C>
     Year Ending June 30,       
       1998                        $ 4,266
       1999                          3,865
       2000                          3,704
       2001                          3,390
       2002                          3,379
       Thereafter                    3,954
                                 ---------
                                   $22,558
                                 =========                               
</TABLE>

 
(12) SALE OF INSTALLMENTS RECEIVABLE

     The Company sold, with limited recourse, certain of its installment
     contracts to two financial institutions for $28,895,000 and $30,210,000
     during fiscal 1996 and 1997, respectively. The financial institutions have
     partial recourse to the Company only upon nonpayment by the customer under
     the installments receivable. The amount of recourse is determined pursuant
     to the provisions of the Company's contracts with the financial
     institutions and varies depending on whether the customers under the
     installment contracts are foreign or domestic entities. Collections of
     these receivables reduce the Company's recourse obligation, as defined.

     At June 30, 1997, the balance of the uncollected principal portion of the
     contracts sold with partial recourse was approximately $57,783,000. The
     Company's potential recourse obligations related to these contracts is
     approximately $6,594,000. In addition, the Company is obligated to pay
     additional costs to the financial institutions in the event of default by
     the customer.


(13) COMMITMENTS

     The Company has entered into agreements with six executive officers
     providing for the payment of cash and other benefits in certain events of
     their voluntary or involuntary termination within three years following a
     change in control. Payment under these agreements would consist of a lump
     sum equal to approximately three years of each executive's annual taxable
     compensation. The agreements also provide that the payment would be
     increased in the event that it would subject the officer to excise tax as a
     parachute payment under the federal tax code. The increase would be equal
     to the additional tax liability imposed on the executive as a result of the
     payment.

                                       F-27
<PAGE>   59
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)



(14) RETIREMENT PLAN

     The Company maintains a defined contribution retirement plan under Section
     401(k) of the Internal Revenue Code covering all eligible employees, as
     defined. Under the plan, a participant may elect to defer receipt of a
     stated percentage of his or her compensation, subject to limitation under
     the Internal Revenue Code, which would otherwise be payable to the
     participant for any plan year. The Company may make discretionary
     contributions to this Plan. No such contributions were made during 1995,
     1996 and 1997. During 1997, the plan was modified to provide, among other
     changes, for the Company to make matching contributions equal to 25% of
     pretax employee contributions up to a maximum of 6% of an employee's
     salary. During 1997, the Company made matching contributions of
     approximately $385,000.

     The Company does not provide postretirement benefits to any employees as
     defined under SFAS No. 106, Employers' Accounting for Postretirement
     Benefits Other Than Pensions.

(15) JOINT VENTURES

     In May 1993, the Company entered into an Equity Joint Venture agreement
     with China Petrochemical Technology Company to form a limited liability
     company governed by the laws of the People's Republic of China. This
     company has the nonexclusive right to distribute the Company's products
     within the People's Republic of China. The Company invested $300,000 on
     August 6, 1993, which represents a 30% equity interest in the joint
     venture.

     In November 1993, the Company invested approximately $100,000 in a
     Cyprus-based corporate joint venture, representing approximately a 14%
     equity interest. The Company had a two-year option to purchase additional
     shares in the joint venture corporation, which would increase its equity
     interest to 22.5%. In December 1995, the Company exercised its option to
     acquire these additional shares for approximately $125,000.

     The Company is accounting for these investments using the equity method.
     The net investments are included in other assets in the accompanying
     consolidated balance sheets. In the accompanying consolidated statements of
     operations for the years ended June 30, 1995, 1996 and 1997, the Company
     has recognized approximately $22,000, $10,000 and $26,000, respectively, in
     net income as its portion of the income from these joint ventures.




                                       F-28
<PAGE>   60
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)



(16) ACCRUED EXPENSES

     Accrued expenses in the accompanying consolidated balance sheets consist of
the following (in thousands):

<TABLE>
<CAPTION>
                                                 JUNE 30,
                                             1996        1997

<S>                                       <C>         <C>    
      Income taxes                          $ 2,728     $ 6,711
      Payroll and payroll-related             4,743       3,302
      Royalties and outside commissions       4,149       2,051
      Other                                   4,392       4,508
                                          ---------   ---------

                                            $16,012     $16,572
                                          =========   =========
</TABLE>


(17) RELATED PARTY TRANSACTION

     Smart Finance & Company, a company of which a director of the Company is
the President provides advisory services to the Company from time to time. In
fiscal 1996 and 1997, payments of approximately $72,000 and $222,000,
respectively, were made by the Company to Smart Finance & Company as
compensation for services rendered.

(18) FINANCIAL INFORMATION BY GEOGRAPHIC AREA

     Domestic and export sales as a percentage of total revenues are as follows:

<TABLE>
<CAPTION>
                                       YEARS ENDED JUNE 30,
                               1995          1996          1997
                                                        
<S>                            <C>           <C>           <C>  
     United States              48.1%         54.6%         47.7%
     Europe                     30.6          26.7          32.4
     Japan                      12.3           9.6           9.2
     Other                       9.0           9.1          10.7
                               -----         -----         -----
                               100.0%        100.0%        100.0%
                               =====         =====         =====
</TABLE>
                                                    

                                       F-29
<PAGE>   61
                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  JUNE 30, 1997

                                   (Continued)



     Revenues, income (loss) from operations and identifiable assets for the
     Company's United States, European and Asian operations are as follows (in
     thousands). The Company has intercompany distribution arrangements with its
     subsidiaries. The basis for these arrangements, disclosed below as
     transfers between geographic locations, is cost plus a specified percentage
     for services and a commission rate for sales generated in the geographic
     region.

<TABLE>
<CAPTION>
                                UNITED       EUROPE         ASIA       ELIMINATIONS  CONSOLIDATED
                                STATES                                            
<S>                           <C>           <C>           <C>          <C>           <C>
Year ended June 30, 1995 -                                                             
  Revenues                    $  56,951     $     547     $      --    $      --     $  57,498
  Transfers between                  --        10,912         4,463      (15,375)           --
    geographic locations      ---------     ---------     ---------    ---------     ---------

      Total revenues          $  56,951     $  11,459     $   4,463    $ (15,375)    $  57,498
                              =========     =========     =========    =========     =========

Income from operations        $   5,126     $   1,112     $     313    $      --     $   6,551
                              =========     =========     =========    =========     =========

Identifiable assets           $  71,143     $   4,087     $     416    $      51     $  75,697
                              =========     =========     =========    =========     =========

Year ended June 30, 1996 -

  Revenues                    $ 100,958     $   2,643     $       8    $      --     $ 103,609
  Transfers between                  --        13,474         4,645      (18,119)           --
   geographic locations       ---------     ---------     ---------    ---------     ---------

      Total revenues          $ 100,958     $  16,117     $   4,653    $ (18,119)    $ 103,609
                              =========     =========     =========    =========     =========

Income (loss) from            $ (11,449)    $    (267)    $      15    $      --     $ (11,701)
operations                    =========     =========     =========    =========     =========


Identifiable assets           $ 183,550     $  11,172     $     414    $ (45,948)    $ 149,188
                              =========     =========     =========    =========     =========

Year ended June 30, 1997 -
  Revenues                    $ 171,644     $   8,611     $      44    $      --     $ 180,299
  Transfers between                  --        22,812         8,099      (30,911)           --
   geographic locations       ---------     ---------     ---------    ---------     ---------

      Total revenues          $ 171,644     $  31,423     $   8,143    $ (30,911)    $ 180,299
                              =========     =========     =========    =========     =========

Income (loss) from            $  14,620     $   2,578     $     594    $      --     $  17,792
  operations                   ========      ========        ======     ========       =======

Identifiable assets           $ 221,544     $   7,094     $   1,191    $ (53,391)    $ 176,438
                              =========     =========     =========    =========     =========
</TABLE>


                                       F-30

                                                                                
<PAGE>   62
              REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS ON SCHEDULE



To Aspen Technology, Inc.:

We have audited, in accordance with generally accepted auditing standards, the
consolidated financial statements of Aspen Technology, Inc. and subsidiaries,
included in this Form 10-K, and have issued our report thereon dated August 13,
1997. Our audit was made for the purpose of forming an opinion on the basic
financial statements taken as a whole. The schedule listed in Item 14(a)-2 is
the responsibility of the Company's management, is presented for purposes of
complying with the Securities and Exchange Commission's rules and is not part of
the basic financial statements. This schedule has been subjected to the auditing
procedures applied in the audit of the basic financial statements and, in our
opinion, fairly states, in all material respects, the financial data required to
be set forth therein, in relation to the basic financial statements taken as a
whole.




                                                     ARTHUR ANDERSEN LLP

Boston, Massachusetts
August 13, 1997 (Except 
with respect to the matters 
discussed in footnote 3(g)
as to which the date is 
August 28, 1997)






                                      S-1
<PAGE>   63
                                                                     SCHEDULE II



                     ASPEN TECHNOLOGY, INC. AND SUBSIDIARIES

                        VALUATION AND QUALIFYING ACCOUNTS



<TABLE>
<CAPTION>
        DESCRIPTION         BALANCE,     CHARGED      DEDUCTIONS     OTHER       BALANCE,
                            BEGINNING    TO COSTS                                 END OF
                            OF PERIOD    AND                                      PERIOD
                                         EXPENSES                              

<S>                         <C>          <C>          <C>          <C>          <C>     
ALLOWANCE FOR DOUBTFUL                                                          
ACCOUNTS:                                                                       

  June 30, 1995             $ 84,000     $       -     $      -    $      -     $ 84,000
                                                                                
  June 30, 1996               84,000       200,000       (2,315)    449,000(1)   730,685
                                                                                
  June 30, 1997              730,685             -     (222,850)    211,882(2)   719,717
</TABLE>


                                                                                
                                                                              
(1) Relates to amounts acquired in the acquisitions of Setpoint and DMCC.
(2) Relates to amounts acquired in the acquisitions of B-JAC and Bechtel PIMS.




                                      S-2

<PAGE>   1
                                                                   EXHIBIT 10.23



                             ASPEN TECHNOLOGY, INC.

                         1996 SPECIAL STOCK OPTION PLAN



      1.    Definitions.  As used in this 1996 Special Stock Option Plan of
Aspen Technology, Inc., the following terms shall have the following meanings:

            1.1. Change in Corporate Control means the date on which any
      individual, corporation, partnership or other person or entity (together
      with its "Affiliates" and "Associates," as defined in Rule 12b-2 under the
      Securities Exchange Act of 1934) "beneficially owns" (as defined in Rule
      13d-3 under the Securities Exchange Act of 1934) in the aggregate 20% or
      more of the outstanding shares of capital stock of the Company entitled to
      vote generally in the election of directors of the Company.

            1.2.  Code means the Internal Revenue Code of 1986, as amended.

            1.3.  Committee means the Compensation Committee of the Company's
      Board of Directors.

            1.4.  Company means Aspen Technology, Inc., a Massachusetts
      corporation.

            1.5. Date of Acquisition means the closing date of an acquisition,
      and if a business is acquired in more than one purchase transaction, the
      last closing date to occur, provided such closings are related
      transactions under a plan for the acquisition of such business by the
      Company.

            1.6. Director means any person on the board of directors of an
      acquired business, excluding however persons who were employed by the
      Company prior to and on the date of acquisition of such business by the
      Company.

            1.7.  Employee means any person employed by an acquired business
      prior to and on the date of acquisition of such business by the Company.

            1.8.  Fair Market Value means the value of a share of Stock of
      the Company on any date as determined by the Committee.

            1.9.  Grant Date means the date on which an Option is granted, as
      specified in Section 7.

            1.10. Incentive Option means an option which qualifies for tax
      treatment under Section 422 of the Code.
<PAGE>   2
            1.11. Major Shareholder means a person who, within the meaning of
      Section 422(b)(6) of the Code, is deemed to own stock possessing more than
      10% of the total combined voting power of all classes of stock of the
      Company (or of its parent or subsidiary corporations).

            1.12. Option means an option to purchase shares of the Stock
      granted under the Plan.

            1.13. Option Agreement means an agreement between the Company and
      an Optionee, setting forth the terms and conditions of an Option.

            1.14. Option Price means the price paid by an Optionee for a
      share of Stock under this Plan.

            1.15. Option Share means any share of Stock of the Company
      transferred to an Optionee upon exercise of an Option pursuant to this
      Plan.

            1.16. Optionee means a person eligible to receive an Option, as
      provided in Section 6, to whom an Option shall have been granted under the
      Plan.

            1.17. Plan means this 1996 Special Stock Option Plan of the
      Company.

            1.18. Related Corporation means a Parent Corporation or a
      Subsidiary Corporation, each as defined in Section 424 of the Code.

            1.19. Stock means common stock, $.10 par value, of the Company.

      2. Purpose. This 1996 Special Stock Option Plan is intended to encourage
ownership of the Stock by Employees, consultants and Directors of businesses
acquired by the Company and to provide additional incentive for them to promote
the success of the Company's business. The Plan is intended to be an incentive
stock option plan within the meaning of Section 422 of the Code, but not all the
Options must be Incentive Options.

      3.    Term of the Plan.  Options under the Plan may be granted not
later than November 30, 2006.

      4. Stock Subject to the Plan. Subject to the provisions of Section 16 of
the Plan, the number of shares of the Stock attributable to the exercise of
Options granted under the Plan plus the number of shares then issuable upon
exercise of outstanding options granted under the Plan shall at no time exceed
250,000. Shares to be issued upon the exercise of Options granted under the Plan
may be either authorized but unissued shares or shares held by the Company in
its treasury. If any Option expires or terminates for any reason without having
been exercised in full, the shares not purchased thereunder shall again be
available for Options thereafter to be granted.
<PAGE>   3
      5. Administration. The Plan shall be administered by the Committee.
Subject to the provisions of the Plan, the Committee shall have complete
authority, in its discretion, to make the following determinations with respect
to each Option to be granted by the Company: (a) the Employee or consultant or
Director of an acquired business to receive the Option; (b) the time of granting
the Option; (c) the number of shares subject thereto; (d) the Option Price; (e)
the Option period; and (f) if the Optionee is an employee after the acquisition
is effected, whether the Option is an Incentive Option. In making such
determinations, the Committee may take into account the nature of the services
rendered by the Employees and consultants and Directors, their present and
potential contributions to the success of the Company and its Related
Corporations, and such other factors as the Committee in its discretion shall
deem relevant. Subject to the provisions of the Plan, the Committee shall also
have complete authority to interpret the Plan, to prescribe, amend and rescind
rules and regulations relating to it, to determine the terms and provisions of
the respective Option Agreements (which need not be identical), and to make all
other determinations necessary or advisable for the administration of the Plan.
The Committee's determinations on the matters referred to in this Section 5
shall be conclusive.

      6. Eligibility. An Option may be granted only to an Employee, consultant
or Director of a business acquired by the Company. A Major Shareholder shall be
eligible to receive an Incentive Option only if the Option Price is at least
110% of the Fair Market Value on the Grant Date and only if the Incentive Option
expires, to the extent not theretofore exercised, on the fifth anniversary of
the Grant Date.

      7. Time of Granting Options. The granting of an Option shall take place at
the time specified by the Committee, but not later than six months after the
Date of Acquisition with respect to which the grant is made. Only if expressly
so provided by the Committee, shall the Grant Date be the date on which an
Option Agreement shall have been duly executed and delivered by the Company and
the Optionee.

      8. Option Price. The Option Price under each Incentive Option shall be not
less than 100% of the Fair Market Value of the Stock on the Grant Date except
that the Option Price under an Incentive Option granted to a Major Shareholder
must be not less than 110% of the Fair Market Value.

      9. Option Period. No Option may be exercised later than the tenth
anniversary of the Grant Date or, for an Incentive Option granted to a Major
Shareholder, the fifth anniversary of the Grant Date. Unless the Committee
otherwise determines, all Options granted hereunder shall permit the Optionee to
purchase, cumulatively, one-sixteenth of the Option Shares at the end of each
calendar quarter beginning after the Grant Date. Upon a Change in Corporate
Control, each outstanding Option shall immediately become fully exercisable.

      10. Maximum Size of Option. To the extent that the aggregate Fair Market
Value of Stock for which an Incentive Option becomes exercisable by an Optionee
for the first time in any calendar year exceeds $100,000, the Option shall be
treated as a
<PAGE>   4
nonstatutory option, and not an Incentive Option. For purposes of this Section
10, all Options granted to an Optionee by the Company shall be considered in the
order in which they were granted, and the Fair Market Value shall be determined
as of the Grant Dates.

      11. Exercise of Option. An Option may be exercised only by giving written
notice, in the manner provided in Section 20 hereof, specifying the number of
shares as to which the Option is being exercised, accompanied by (a) full
payment for such shares in the form of check or bank draft payable to the order
of the Company, or (b) certificates representing shares of the Stock with a
current Fair Market Value equal to the Option Price of the shares to be
purchased, or (c) irrevocable instructions to a brokerage firm to sell a
sufficient number of the Option Shares to generate the full exercise price plus
all applicable withholding taxes and to pay over to the Company such proceeds of
sale. Receipt by the Company of such notice and payment shall constitute the
exercise of the Option or a part thereof. The Company shall thereafter deliver
or cause to be delivered to the Optionee a certificate or certificates for the
number of shares then being purchased by the Optionee. Such shares shall be
fully paid and nonassessable. If any law or applicable regulation of the
Securities and Exchange Commission or other body having jurisdiction in the
premises shall require the Company or the Optionee to take any action in
connection with shares being purchased upon exercise of the option, exercise of
the option and delivery of the certificate or certificates for such shares shall
be postponed until completion of the necessary action, which shall be taken at
the Company's expense.

      12. Notice of Disposition of Stock Prior to Expiration of Specified
Holding Period. The Company may require that the person exercising an Incentive
Option give a written representation to the Company, satisfactory in form and
substance to its counsel and upon which the Company may reasonably rely, that he
or she will report to the Company any disposition of shares purchased upon
exercise prior to the expiration of the holding periods specified by Section
422(a)(1) of the Code. If and to the extent that the disposition imposes upon
the Company federal, state, local or other withholding tax requirements, or any
such withholding is required to secure for the Company an otherwise available
tax deduction, the Company shall have the right to require that the person
making the disposition remit to the Company an amount sufficient to satisfy
those requirements.

      13. Transferability of Options. Options shall not be transferable,
otherwise than by will or the laws of descent and distribution, and may be
exercised during the life of the Optionee only by the Optionee.

      14. Stock Purchase Agreement. Each Optionee exercising an option, at the
request of the Company, will be required to sign a Stock Purchase Agreement
representing in form satisfactory to counsel for the Company that he or she will
not transfer, sell or otherwise dispose of the Option Shares at any time
purchased by him or her, upon the exercise of any portion of the Option, in a
manner which would violate the Securities Act of 1933, as amended, and the
regulations of the Securities and Exchange Commission thereunder; and the
Company may, at its discretion, make a notation on any
<PAGE>   5
certificates issued upon exercise of options to the effect that such certificate
may not be transferred except after receipt by the Company of an opinion of
counsel satisfactory to it to the effect that such transfer will not violate
such Act and such regulations, and may issue "stop transfer" instructions to its
transfer agent, if any, and make a "stop transfer" notation on its books as
appropriate. Such Stock Purchase Agreement shall include such other provisions
as the Committee may determine are appropriate.

      15. Termination of Employment. In the event that the Optionee's employment
or consulting relationship is terminated for any reason other than death or the
Optionee's employer is no longer the Company or a Related Corporation, the
Option, to the extent exercisable at termination, may be exercised by the
Optionee at any time within 30 days after termination unless terminated earlier
by its terms. If termination results from the death of the Optionee, the Option,
to the extent exercisable at the date of death, may be exercised by the person
to whom the Option is transferred by will or the applicable laws of descent and
distribution, at any time within 12 months after the date of death, unless
terminated earlier by its terms. Military or sick leave shall not be deemed a
termination of employment provided that it does not exceed the longer of 90 days
or the period during which the absent employee's re-employment rights are
guaranteed by statute or by contract.

      16. Adjustment of Number of Shares. Each Option Agreement shall provide
that in the event of any capital adjustments including stock splits, stock
contractions, stock dividends, reclassifications, exchanges and substitutions,
occurring after the date of the option and prior to the exercise in full of the
option, the number of shares for which the option may be exercised and the price
per share shall be proportionately adjusted and in the event of any resulting
changes in the outstanding Stock, the number of shares of the Stock available
for the purpose of the Plan as stated in Section 4 hereof shall be
correspondingly adjusted.

      17. Stock Reserved. The Company shall at all times during the term of the
Option reserve and keep available such number of shares of the Stock as will be
sufficient to satisfy the requirements of this Plan and shall pay all fees and
expenses necessarily incurred by the Company in connection therewith.

      18. Limitation of Rights in the Option Shares. An Optionee shall not be
deemed for any purpose to be a stockholder of the Company with respect to any of
the Option Shares except to the extent that the Option shall have been exercised
with respect thereto and, in addition, a certificate shall have been issued
therefor and delivered to the Optionee.

      19. Termination and Amendment of the Plan. The Board of Directors of the
Company may at any time terminate the Plan or make such amendment to the Plan as
it shall deem advisable, provided that, except as provided in Section 16, it may
not, without the approval by the holders of a majority of the Stock, change the
classes of persons eligible to receive Options, increase the maximum number of
shares available for option under the Plan or extend the period during which
Options may be granted or exercised.
<PAGE>   6
No termination or amendment of the Plan may, without the consent of the Optionee
to whom any Option shall theretofore have been granted, adversely affect the
rights of such Optionee under such Option. The Company may also, in its
discretion, permit any option to be exercised prior to the date on which it
vests.

      20. Notices. Any communication or notice required or permitted to be given
under the Plan shall be in writing, and mailed by registered or certified mail
or delivered in hand, if to the Company, to its Chief Financial Officer at Ten
Canal Park, Cambridge, MA 02141 and, if to the Optionee, to the address as the
Optionee shall last have furnished to the Company.

<PAGE>   1
                                                                   EXHIBIT 10.24



                            CHANGE IN CONTROL AGREEMENT

      AGREEMENT dated as of August 12, 1997 by and between Aspen Technology,
Inc., a Massachusetts corporation (the "Company"), and Lawrence B. Evans (the
"Executive").

      WHEREAS, the Company considers it essential to the best interests of its
stockholders to foster the continuous employment of key management personnel;
and

      WHEREAS, the Company has determined that appropriate steps should be taken
to reinforce and encourage the continued attention and dedication of members of
the Company's management, including the Executive, to their assigned duties with
the Company without distraction in the face of potentially disturbing
circumstances arising from the possibility of a Change in Control (as defined
herein);

      NOW THEREFORE, in consideration of the premises and the mutual covenants
herein contained, and for other valuable consideration, the Company and the
Executive hereby agree as follows:

      1. Defined Terms. The definitions of capitalized terms used in this
Agreement are provided in the last section hereof.

      2. Term of Agreement. This Agreement shall commence on the date hereof and
shall continue in effect through June 30, 2002. Thereafter, this Agreement shall
be automatically renewed for successive one year terms unless the Company sends
written notice of termination to the Executive at least 60 days before the
expiration date of this Agreement, which termination will be effective at that
expiration date. If a Change in Control shall have occurred during the term of
this Agreement, however, this Agreement shall continue in effect for a period of
three years beyond the last day of the month in which the Change in Control
occurred. Notwithstanding the foregoing provisions of this Section 2, this
Agreement shall terminate, unless earlier terminated in accordance with this
Agreement, (i) one year after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee, upon recommendation of the
Company's chief executive officer, has voted to terminate this Agreement or (ii)
if earlier, immediately after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee has determined that the
Executive's level of responsibility (other than reporting responsibility) has
substantially changed from the Executive's current level of responsibility,
<PAGE>   2
                                       -2-


in either case only if the notification occurs prior to a Potential Change in
Control that results in a Change in Control.

      3.    Payments After Change in Control.

      3.1 If the Executive's employment shall be terminated for any reason
following a Change in Control and during the term of this Agreement, the Company
shall pay the Executive's full salary to the Executive through the Date of
Termination at the rate in effect at the time the Notice of Termination is
given, together with all compensation and benefits payable to the Executive
through the Date of Termination under the terms of any compensation or benefit
plan, program or arrangement maintained by the Company during such period.

      3.2 Subject to Section 3.3, the Company shall pay to the Executive the
payments described in this Section 3.2 (the "Severance Payments") upon the
termination of the Executive's employment following a Change in Control and
during the term of this Agreement, in addition to the payments and benefits
described in Section 3.1, unless such termination is (i) by the Company for
Cause, (ii) by reason of death, (iii) by the Executive without Good Reason, or
(iv) after the Executive shall have attained age 70. In lieu of any further
salary payments to the Executive for periods subsequent to the Date of
Termination and in lieu of any severance benefits otherwise payable to the
Executive under any then existing broad-based employee severance plan, the
Company shall pay to the Executive a lump sum severance payment, in cash, equal
to three times the sum of (x) the higher of the Executive's annual base salary
in effect immediately prior to the occurrence of the event or circumstance upon
which the Notice of Termination is based or in effect immediately prior to the
Change in Control and (y) the higher of the average of the annual bonuses paid
to the Executive for the three years (or the number of years employed, if less)
immediately preceding the occurrence of the event or circumstance upon which the
Notice of Termination is based or the Change in Control. In lieu of any further
life, disability, accident and health insurance benefits otherwise due to the
Executive, the Company shall pay to the Executive a lump sum amount, in cash,
equal to the cost to the Company (as determined by the Company in good faith
with reference to its most recent actual experience) of providing such benefits,
to the extent that the Executive is eligible to receive such benefits
immediately prior to the Notice of Termination, for a period of three years
commencing on the Date of Termination.

      3.3 The payments provided for in Section 3.2 shall be made not later than
the fifth day following the Date of Termination.
<PAGE>   3
                                       -3-


      3.4 The Company also shall pay to the Executive all legal fees and
expenses incurred by the Executive in seeking to obtain or enforce any benefit
or right provided by this Agreement, payable within five business days after
delivery of the Executive's written requests for payment accompanied with such
evidence of fees and expenses incurred as the Company reasonably may require.

      4. Certain Additional Payments by the Company.

      4.1 Notwithstanding any other provisions of this Agreement, in the event
that any payment or benefit received or to be received by the Executive in
connection with a Change in Control or the termination of the Executive's
employment (all such payments and benefits, including the Severance Payments,
the "Total Payments") is determined to be subject (in whole or part) to the
Excise Tax, then the Executive shall be entitled to receive an additional
payment (a "Gross-Up Payment") in an amount such that after payment by the
Executive of all taxes (including any interest or penalties imposed with respect
to such taxes), including without limitation any income taxes and Excise Tax
imposed upon the Gross-Up Payment, the Executive retains an amount equal to the
Total Payments. Notwithstanding the foregoing provisions of this Section 4.1, if
it shall be determined that the Executive is entitled to a Gross-Up Payment, but
that the Total Payments do not exceed 110% of the greatest amount (the "Reduced
Amount") that could be paid to the Executive such that the receipt thereof would
not give rise to any Excise Tax, then no Gross-Up Payment shall be made to the
Executive and the Total Payments shall be reduced to the Reduced Amount.

      4.2 All determinations required to be made under this Section 4, including
whether and when a Gross-Up Payment is required and the amount of such Gross-Up
Payment and the assumptions to be utilized in arriving at such determination,
shall be made by the Company's accountants or such other certified public
accounting firm reasonably acceptable to the Company as may be designated by the
Executive (the "Accounting Firm") which shall provide detailed supporting
calculations both to the Company and the Executive.

      5. Termination Procedures.

      5.1 Notice of Termination. After a Change in Control and during the term
of this Agreement, any purported termination of the Executive's employment
(other than by reason of death) shall be communicated by written Notice of
Termination from one party hereto to the other party hereto in accordance with
Section 8. Further, a Notice of Termination for Cause is required to include a
copy of a resolution duly adopted by the
<PAGE>   4
                                       -4-


affirmative vote of not less than three-quarters of the entire membership of the
Board at a meeting of the Board which was called and held for the purpose of
considering such termination (after reasonable notice to the Executive and an
opportunity for the Executive, together with the Executive's counsel, to be
heard before the Board) finding that, in the good faith opinion of the Board,
the Executive was guilty of conduct set forth in the definition of Cause.

      5.2 Date of Termination. "Date of Termination", with respect to any
purported termination of the Executive's employment after a Change in Control
and during the term of this Agreement, shall mean the date specified in the
Notice of Termination (which, in the case of a termination by the Company
otherwise than for Cause, shall not be less than thirty days and, in the case of
a termination by the Executive, shall not be less than fifteen days nor more
than sixty days, respectively, from the date such Notice of Termination is
given).

      6. No Mitigation. If the Executive's employment by the Company is
terminated during the term of this Agreement, the Executive is not required to
seek other employment or to attempt in any way to reduce any amounts payable to
the Executive by the Company pursuant to Section 3. Further, the amount of any
payment or benefit provided for in Section 3 shall not be reduced by any
compensation earned by the Executive as the result of employment by another
employer, by retirement benefits, by offset against any amount claimed to be
owed by the Executive to the Company, or otherwise.

      7. Executive's Covenants. The Executive agrees that, subject to the terms
and conditions of this Agreement, in the event of a Potential Change in Control
during the term of this Agreement, the Executive will remain in the employ of
the Company until the earliest of (i) a date which is six months from the date
of such Potential Change of Control, (ii) the date of a Change in Control, (iii)
the date of termination by the Executive of the Executive's employment for Good
Reason (determined by treating the Potential Change in Control as a Change in
Control in applying the definition of Good Reason), by reason of death or
Retirement; or (iv) the termination by the Company of the Executive's employment
for any reason.

      8. Successors; Binding Agreement.

      8.1 In addition to any obligations imposed by law upon any successor to
the Company, the Company will require any successor (whether direct or indirect,
by purchase, merger, consolidation or otherwise) to all or substantially all of
the business and/or assets of the
<PAGE>   5
                                       -5-


Company to expressly assume and agree to perform this Agreement in the same
manner and to the same extent that the Company would be required to perform it
if no such succession had taken place. Failure of the Company to obtain such
assumption and agreement prior to the effectiveness of any such succession shall
be a breach of this Agreement and shall entitle the Executive to compensation
from the Company in the same amount and on the same terms as the Executive would
be entitled to hereunder if the Executive were to terminate the Executive's
employment for Good Reason after a Change in Control, except that, for purposes
of implementing the foregoing, the date on which any such succession becomes
effective shall be deemed the Date of Termination.

      8.2 This Agreement shall inure to the benefit of and be enforceable by the
Executive's personal or legal representatives. If the Executive shall die while
any amount would still be payable to the Executive hereunder (other than amounts
which, by their terms, terminate upon the death of the Executive) if the
Executive had continued to live, all such amounts, unless otherwise provided
herein, shall be paid in accordance with the terms of this Agreement to the
Executive's representatives.

      9. Notices. For the purpose of this Agreement, notices and all other
communications provided for in the Agreement shall be in writing and shall be
deemed to have been duly given when delivered or mailed by United States
certified or registered mail, return receipt requested, postage prepaid,
addressed to the respective addresses set forth below, or to such other address
as either party may have furnished to the other in writing in accordance
herewith, except that notice of change of address shall be effective only upon
actual receipt:

                  To the Company:
                  Aspen Technology, Inc.
                  Ten Canal Park
                  Cambridge, MA  02141

                  Attention:  General Counsel

                  To the Executive:
                  Lawrence B. Evans
                  29 Coolidge Hill Road
                  Cambridge, MA  02138

      10. Miscellaneous. No provision of this Agreement may be modified, waived
or discharged unless such waiver, modification or
<PAGE>   6
                                       -6-


discharge is agreed to in writing and signed by the Executive and such officer
as may be specifically designated by the Board. Except as expressly provided
herein, no waiver by either party hereto at any time of any breach by the other
party hereto of, or compliance with, any condition or provision of this
Agreement to be performed by such other party shall be deemed a waiver of
similar or dissimilar provisions or conditions at the same or at any prior or
subsequent time. No agreements or representations, oral or otherwise, express or
implied, with respect to the subject matter hereof have been made by either
party which are not expressly set forth in this Agreement. The validity,
interpretation, construction and performance of this Agreement shall be governed
by the laws of the Commonwealth of Massachusetts, and this Agreement shall be an
instrument under seal. All references to sections of the Exchange Act or the
Code shall be deemed also to refer to any successor provisions to such sections.
Any payments provided for hereunder shall be paid net of any applicable
withholding required under federal, state or local law and any additional
withholding to which the Executive has agreed.

      11. Settlement of Disputes; Arbitration. All claims by the Executive for
benefits under this Agreement shall be directed to and determined by the Board
and shall be in writing. Any denial by the Board of a claim for benefits under
this Agreement shall be delivered to the Executive in writing and shall set
forth the specific reasons for the denial and the specific provisions of this
Agreement relied upon. Any further dispute or controversy arising under or in
connection with this Agreement shall be settled exclusively by arbitration in
Boston, Massachusetts, in accordance with the rules of the American Arbitration
Association then in effect. Judgment may be entered on the arbitrator' s award
in any court having jurisdiction. The Executive shall, however, be entitled to
seek specific performance of the Executive's right to be paid until the Date of
Termination during the pendency of any dispute or controversy arising under or
in connection with this Agreement.

      12.   Definitions.  For purposes of this Agreement, the following terms
shall have the-meanings indicated below:

                  "Beneficial owner" shall have the meaning defined in Rule
      13d-3 under the Exchange Act.

                  "Board" shall mean the Board of Directors of the Company.

                  "Cause" for termination by the Company of the Executive's
      employment, after any Change in Control, shall mean (i) the willful and
      continued failure by the Executive to
<PAGE>   7
                                       -7-


      substantially perform the Executive's duties with the Company (other than
      any such failure resulting from the Executive's incapacity due to physical
      or mental illness or any such actual or anticipated failure after the
      issuance of a Notice of Termination for Good Reason by the Executive)
      after a written demand for substantial performance is delivered to the
      Executive by the Board, which demand specifically identifies the manner in
      which the Board believes that the Executive has not substantially
      performed the Executive's duties, or (ii) the willful engaging by the
      Executive in gross misconduct which is demonstrably and materially
      injurious to the Company or any of its subsidiaries, monetarily or
      otherwise. No act, or failure to act, on the Executive's part shall be
      deemed "willful" unless done, or omitted to be done, by the Executive not
      in good faith and without reasonable belief that the Executive's act, or
      failure to act, was in the best interest of the Company.

            A "Change in Control" shall be deemed to have occurred if the
      conditions set forth in any one of the following paragraphs shall have
      been satisfied:

                  (a) Continuing Directors constitute two-thirds or less of the
            membership of the Board, whether as the result of a proxy contest or
            for any other reason or reasons; or

                  (b) Any Person is or becomes the Beneficial owner, directly or
            indirectly, of securities of the Company representing twenty-five
            percent or more of the combined voting power of the Company's then
            outstanding voting securities; or

                  (c) There is a change in control of the Company of a nature
            that would be required to be reported on Form 8-K or item 6(e) of
            Schedule 14A of Regulation 14A or any similar item, schedule or form
            under the Exchange Act, as in effect at the time of the change,
            whether or not the Company is then subject to such reporting
            requirement, including without limitation any merger or
            consolidation of the Company with any other corporation, other than
            (i) a merger or consolidation which would result in the voting
            securities of the Company outstanding immediately prior thereto
            continuing to represent (either by remaining outstanding or by being
            converted into voting securities of the surviving or parent entity)
            fifty-one percent or more of the combined voting power of the voting
            securities (entitled to vote generally for the
<PAGE>   8
                                       -8-


            election of directors) of the Company or such surviving or parent
            entity outstanding immediately after such merger or consolidation
            and which would result in those persons who are Continuing Directors
            immediately prior to such merger or consolidation constituting more
            than two-thirds of the membership of the Board or the board of such
            surviving or parent entity immediately after, or subsequently at any
            time as contemplated by or as a result of, such merger or
            consolidation or (ii) a merger or consolidation effected to
            implement a recapitalization of the company (or similar transaction)
            in which no Person acquired twenty-five percent or more of the
            combined voting power of the Company's then outstanding securities;
            or

                  (d) the stockholders of the Company approve a plan of complete
            liquidation of the Company or an agreement for the sale or
            disposition by the Company of all or substantially all of the
            Company's assets (or any transaction having a similar effect).

      "Code" shall mean the Internal Revenue Code of 1986, as amended from time
to time.

      "Company" shall mean Aspen Technology, Inc. and any successor to its
business and/or assets which assumes or agrees to perform this Agreement, by
operation of law or otherwise.

      "Compensation Committee" shall mean the Compensation and Nominating
Committee of the Board.

      "Continuing Director" shall mean any director (i) who has continuously
been a member of the Board since not later than the date of a Potential Change
in Control or (ii) who is a successor of a director described in clause (i), if
such successor (and any intervening successor) shall have been recommended or
elected to succeed a Continuing Director by a majority of the then Continuing
Directors.

      "Date of Termination" shall have the meaning stated in Section 5.2
hereof.

      "Exchange Act" shall mean the Securities Exchange Act of 1934, as amended
from time to time.

      "Excise Tax" shall mean the tax imposed by Section 4999 of the Code.
<PAGE>   9
                                       -9-


      "Executive" shall mean the individual named in the first paragraph of
this Agreement.

      "Good Reason" for termination by the Executive of the Executive's
employment shall mean the occurrence (without the Executive's express written
consent) of any one of the following acts or failures to act by the Company
unless, in the case of any act or failure to act described in paragraph (a),
(e), (f) or (g) below, such act or failure to act is corrected prior to the Date
of Termination specified in the Notice of Termination given in respect thereof
or, in the case of paragraph (c) below, such act is not objected to in writing
by the Executive within four months after notification by the Company to the
Executive of the Company's intention to take the action contemplated by such
paragraph (c):

                  (a) the assignment to the Executive of any duties inconsistent
            with the Executive's status as a senior executive officer of the
            Company or a meaningful alteration, adverse to the Executive, in the
            nature or status of the Executive's responsibilities (other than
            reporting responsibilities) from those in effect immediately prior
            to the Change in Control;

                  (b) a reduction by the Company in the Executive's annual base
            salary as in effect on the date hereof or as the same may be
            increased from time to time except for across-the-board salary
            reductions similarly affecting all senior executives of the Company
            and all senior executives of any Person in control of the Company;

                  (c) the Company's requiring the Executive to be based anywhere
            other than the Boston Metropolitan Area (or, if different, the
            metropolitan area in which the Company's principal executive offices
            are located immediately prior to the Change in Control) except for
            required travel on the Company business to an extent substantially
            consistent with the Executive's present business travel obligations;

                  (d) the failure by the Company, without the Executive's
            consent, to pay to the Executive any portion of the Executive's
            current compensation, or to pay to the Executive any portion of an
            installment of deferred compensation under any deferred compensation
            program of the Company, within fourteen days of the date such
            compensation is due;

                  (e) the failure by the Company to continue in effect any
            compensation plan in which the Executive participates
<PAGE>   10
                                      -10-


            immediately prior to the Change in Control which is material to the
            Executive's total compensation, or the failure by the Company to
            continue the Executive's participation therein on a basis not
            materially less favorable, both in terms of the amount of benefits
            provided and the level of the Executive's participation relative to
            other participants, as existed at the time of the Change in Control;

                  (f) the failure by the Company to continue to provide the
            Executive with benefits substantially similar to those enjoyed by
            the Executive under any of the Company' s pension, life insurance,
            medical, health and accident, or disability plans in which the
            Executive was participating at the time of the Change in Control,
            the taking of any action by the Company which would directly or
            indirectly materially reduce any of such benefits or deprive the
            Executive of any material fringe benefit enjoyed by the Executive at
            the time of the Change in Control, or the failure by the Company to
            provide the Executive with the number of paid vacation days to which
            the Executive is entitled on the basis of years of service with the
            Company in accordance with the Company's normal vacation policy in
            effect at the time of the Change in Control; or

                  (g) any purported termination of the Executive's employment
            which is not effected pursuant to a Notice of Termination satisfying
            the requirements of Section 5.1.

      "Notice of Termination" shall have the meaning stated in Section 5.1.

      "Person" shall have the meaning given in Section 3(a)(9) of the Exchange
Act, as modified and used in Sections 13(d) and 14(d). thereof; however, a
Person shall not include (i) the Company or any of its subsidiaries, (ii) a
trustee or other fiduciary holding securities under an employee benefit plan of
the Company or any of its subsidiaries, (iii) an underwriter temporarily holding
securities pursuant to a registered offering of such securities in accordance
with an agreement with the Company, or (iv) a corporation owned, directly or
indirectly, by the stockholders of the Company in substantially the same
proportions as their ownership of stock of the Company.

      "Potential Change in Control" shall be deemed to have occurred if the
conditions set forth in any one of the following paragraphs shall have been
satisfied:
<PAGE>   11
                                      -11-


                  (a)   the Company enters into an agreement, the
            consummation of which would result in the occurrence of a Change
            in Control;

                  (b) the Company or any Person publicly announces an intention
            to take or to consider taking actions which, if consummated, would
            constitute a Change in Control;

                  (c) any Person becomes the Beneficial Owner, directly or
            indirectly, of securities of the Company representing fifteen
            percent or more of the combined voting power of the Company's then
            outstanding securities (entitled to vote generally for the election
            of directors); or

                  (d) the Board adopts a resolution to the effect that, for
            purposes of this Agreement, a Potential Change in Control has
            occurred.

      "Severance Payments" shall mean those payments described in Section 3.2
hereof.

      "Total Payments" shall mean those payments described in Section 4 hereof.

      IN WITNESS WHEREOF, the Company and the Executive have executed and
delivered this Agreement on the date first written above.



                             ASPEN TECHNOLOGY, INC.



                              By:_______________________________________



                                 _______________________________________
                                          Lawrence B. Evans


<PAGE>   1
                                                                   Exhibit 10.25

                           CHANGE IN CONTROL AGREEMENT

         AGREEMENT dated as of August 12, 1997 by and between Aspen Technology,
Inc., a Massachusetts corporation (the "Company"), and Joseph F. Boston (the
"Executive").

         WHEREAS, the Company considers it essential to the best interests of
its stockholders to foster the continuous employment of key management
personnel; and

         WHEREAS, the Company has determined that appropriate steps should be
taken to reinforce and encourage the continued attention and dedication of
members of the Company's management, including the Executive, to their assigned
duties with the Company without distraction in the face of potentially
disturbing circumstances arising from the possibility of a Change in Control (as
defined herein);

         NOW THEREFORE, in consideration of the premises and the mutual
covenants herein contained, and for other valuable consideration, the Company
and the Executive hereby agree as follows:

         1. Defined Terms. The definitions of capitalized terms used in this
Agreement are provided in the last section hereof.

         2. Term of Agreement. This Agreement shall commence on the date hereof
and shall continue in effect through June 30, 2002. Thereafter, this Agreement
shall be automatically renewed for successive one year terms unless the Company
sends written notice of termination to the Executive at least 60 days before the
expiration date of this Agreement, which termination will be effective at that
expiration date. If a Change in Control shall have occurred during the term of
this Agreement, however, this Agreement shall continue in effect for a period of
three years beyond the last day of the month in which the Change in Control
occurred. Notwithstanding the foregoing provisions of this Section 2, this
Agreement shall terminate, unless earlier terminated in accordance with this
Agreement, (i) one year after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee, upon recommendation of the
Company's chief executive officer, has voted to terminate this Agreement or (ii)
if earlier, immediately after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee has determined that the
Executive's level of responsibility (other than reporting responsibility) has
substantially changed from the Executive's current level of responsibility,
<PAGE>   2
                                       -2-


in either case only if the notification occurs prior to a Potential Change in
Control that results in a Change in Control.

         3. Payments After Change in Control.

         3.1 If the Executive's employment shall be terminated for any reason
following a Change in Control and during the term of this Agreement, the Company
shall pay the Executive's full salary to the Executive through the Date of
Termination at the rate in effect at the time the Notice of Termination is
given, together with all compensation and benefits payable to the Executive
through the Date of Termination under the terms of any compensation or benefit
plan, program or arrangement maintained by the Company during such period.

         3.2 Subject to Section 3.3, the Company shall pay to the Executive the
payments described in this Section 3.2 (the "Severance Payments") upon the
termination of the Executive's employment following a Change in Control and
during the term of this Agreement, in addition to the payments and benefits
described in Section 3.1, unless such termination is (i) by the Company for
Cause, (ii) by reason of death, (iii) by the Executive without Good Reason, or
(iv) after the Executive shall have attained age 70. In lieu of any further
salary payments to the Executive for periods subsequent to the Date of
Termination and in lieu of any severance benefits otherwise payable to the
Executive under any then existing broad-based employee severance plan, the
Company shall pay to the Executive a lump sum severance payment, in cash, equal
to three times the sum of (x) the higher of the Executive's annual base salary
in effect immediately prior to the occurrence of the event or circumstance upon
which the Notice of Termination is based or in effect immediately prior to the
Change in Control and (y) the higher of the average of the annual bonuses paid
to the Executive for the three years (or the number of years employed, if less)
immediately preceding the occurrence of the event or circumstance upon which the
Notice of Termination is based or the Change in Control. In lieu of any further
life, disability, accident and health insurance benefits otherwise due to the
Executive, the Company shall pay to the Executive a lump sum amount, in cash,
equal to the cost to the Company (as determined by the Company in good faith
with reference to its most recent actual experience) of providing such benefits,
to the extent that the Executive is eligible to receive such benefits
immediately prior to the Notice of Termination, for a period of three years
commencing on the Date of Termination.

         3.3 The payments provided for in Section 3.2 shall be made not later
than the fifth day following the Date of Termination.

<PAGE>   3
                                       -3-


         3.4 The Company also shall pay to the Executive all legal fees and
expenses incurred by the Executive in seeking to obtain or enforce any benefit
or right provided by this Agreement, payable within five business days after
delivery of the Executive's written requests for payment accompanied with such
evidence of fees and expenses incurred as the Company reasonably may require.

         4. Certain Additional Payments by the Company.

         4.1 Notwithstanding any other provisions of this Agreement, in the
event that any payment or benefit received or to be received by the Executive in
connection with a Change in Control or the termination of the Executive's
employment (all such payments and benefits, including the Severance Payments,
the "Total Payments") is determined to be subject (in whole or part) to the
Excise Tax, then the Executive shall be entitled to receive an additional
payment (a "Gross-Up Payment") in an amount such that after payment by the
Executive of all taxes (including any interest or penalties imposed with respect
to such taxes), including without limitation any income taxes and Excise Tax
imposed upon the Gross-Up Payment, the Executive retains an amount equal to the
Total Payments. Notwithstanding the foregoing provisions of this Section 4.1, if
it shall be determined that the Executive is entitled to a Gross-Up Payment, but
that the Total Payments do not exceed 110% of the greatest amount (the "Reduced
Amount") that could be paid to the Executive such that the receipt thereof would
not give rise to any Excise Tax, then no Gross-Up Payment shall be made to the
Executive and the Total Payments shall be reduced to the Reduced Amount.

         4.2 All determinations required to be made under this Section 4,
including whether and when a Gross-Up Payment is required and the amount of such
Gross-Up Payment and the assumptions to be utilized in arriving at such
determination, shall be made by the Company's accountants or such other
certified public accounting firm reasonably acceptable to the Company as may be
designated by the Executive (the "Accounting Firm") which shall provide detailed
supporting calculations both to the Company and the Executive.

         5. Termination Procedures.

         5.1 Notice of Termination. After a Change in Control and during the
term of this Agreement, any purported termination of the Executive's employment
(other than by reason of death) shall be communicated by written Notice of
Termination from one party hereto to the other party hereto in accordance with
Section 8. Further, a Notice of Termination for Cause is required to include a
copy of a resolution duly adopted by the
<PAGE>   4
                                        -4-


affirmative vote of not less than three-quarters of the entire membership of the
Board at a meeting of the Board which was called and held for the purpose of
considering such termination (after reasonable notice to the Executive and an
opportunity for the Executive, together with the Executive's counsel, to be
heard before the Board) finding that, in the good faith opinion of the Board,
the Executive was guilty of conduct set forth in the definition of Cause.

         5.2 Date of Termination. "Date of Termination", with respect to any
purported termination of the Executive's employment after a Change in Control
and during the term of this Agreement, shall mean the date specified in the
Notice of Termination (which, in the case of a termination by the Company
otherwise than for Cause, shall not be less than thirty days and, in the case of
a termination by the Executive, shall not be less than fifteen days nor more
than sixty days, respectively, from the date such Notice of Termination is
given).

         6. No Mitigation. If the Executive's employment by the Company is
terminated during the term of this Agreement, the Executive is not required to
seek other employment or to attempt in any way to reduce any amounts payable to
the Executive by the Company pursuant to Section 3. Further, the amount of any
payment or benefit provided for in Section 3 shall not be reduced by any
compensation earned by the Executive as the result of employment by another
employer, by retirement benefits, by offset against any amount claimed to be
owed by the Executive to the Company, or otherwise.

         7. Executive's Covenants. The Executive agrees that, subject to the
terms and conditions of this Agreement, in the event of a Potential Change in
Control during the term of this Agreement, the Executive will remain in the
employ of the Company until the earliest of (i) a date which is six months from
the date of such Potential Change of Control, (ii) the date of a Change in
Control, (iii) the date of termination by the Executive of the Executive's
employment for Good Reason (determined by treating the Potential Change in
Control as a Change in Control in applying the definition of Good Reason), by
reason of death or Retirement; or (iv) the termination by the Company of the
Executive's employment for any reason.

         8. Successors; Binding Agreement.

         8.1 In addition to any obligations imposed by law upon any successor to
the Company, the Company will require any successor (whether direct or indirect,
by purchase, merger, consolidation or otherwise) to all or substantially all of
the business and/or assets of the
<PAGE>   5
                                       -5-


Company to expressly assume and agree to perform this Agreement in the same
manner and to the same extent that the Company would be required to perform it
if no such succession had taken place. Failure of the Company to obtain such
assumption and agreement prior to the effectiveness of any such succession shall
be a breach of this Agreement and shall entitle the Executive to compensation
from the Company in the same amount and on the same terms as the Executive would
be entitled to hereunder if the Executive were to terminate the Executive's
employment for Good Reason after a Change in Control, except that, for purposes
of implementing the foregoing, the date on which any such succession becomes
effective shall be deemed the Date of Termination.

         8.2 This Agreement shall inure to the benefit of and be enforceable by
the Executive's personal or legal representatives. If the Executive shall die
while any amount would still be payable to the Executive hereunder (other than
amounts which, by their terms, terminate upon the death of the Executive) if the
Executive had continued to live, all such amounts, unless otherwise provided
herein, shall be paid in accordance with the terms of this Agreement to the
Executive's representatives.

         9. Notices. For the purpose of this Agreement, notices and all other
communications provided for in the Agreement shall be in writing and shall be
deemed to have been duly given when delivered or mailed by United States
certified or registered mail, return receipt requested, postage prepaid,
addressed to the respective addresses set forth below, or to such other address
as either party may have furnished to the other in writing in accordance
herewith, except that notice of change of address shall be effective only upon
actual receipt:

                           To the Company:
                           Aspen Technology, Inc.
                           Ten Canal Park
                           Cambridge, MA  02141

                           Attention:  General Counsel

                           To the Executive:
                           Joseph F. Boston
                           19 Battle Flagg Road
                           Bedford, MA  01730

         10. Miscellaneous. No provision of this Agreement may be modified,
waived or discharged unless such waiver, modification or
<PAGE>   6
                                       -6-


discharge is agreed to in writing and signed by the Executive and such officer
as may be specifically designated by the Board. Except as expressly provided
herein, no waiver by either party hereto at any time of any breach by the other
party hereto of, or compliance with, any condition or provision of this
Agreement to be performed by such other party shall be deemed a waiver of
similar or dissimilar provisions or conditions at the same or at any prior or
subsequent time. No agreements or representations, oral or otherwise, express or
implied, with respect to the subject matter hereof have been made by either
party which are not expressly set forth in this Agreement. The validity,
interpretation, construction and performance of this Agreement shall be governed
by the laws of the Commonwealth of Massachusetts, and this Agreement shall be an
instrument under seal. All references to sections of the Exchange Act or the
Code shall be deemed also to refer to any successor provisions to such sections.
Any payments provided for hereunder shall be paid net of any applicable
withholding required under federal, state or local law and any additional
withholding to which the Executive has agreed.

         11. Settlement of Disputes; Arbitration. All claims by the Executive
for benefits under this Agreement shall be directed to and determined by the
Board and shall be in writing. Any denial by the Board of a claim for benefits
under this Agreement shall be delivered to the Executive in writing and shall
set forth the specific reasons for the denial and the specific provisions of
this Agreement relied upon. Any further dispute or controversy arising under or
in connection with this Agreement shall be settled exclusively by arbitration in
Boston, Massachusetts, in accordance with the rules of the American Arbitration
Association then in effect. Judgment may be entered on the arbitrator' s award
in any court having jurisdiction. The Executive shall, however, be entitled to
seek specific performance of the Executive's right to be paid until the Date of
Termination during the pendency of any dispute or controversy arising under or
in connection with this Agreement.

         12. Definitions. For purposes of this Agreement, the following terms
shall have the-meanings indicated below:

                           "Beneficial owner" shall have the meaning defined in
         Rule 13d-3 under the Exchange Act.

                           "Board" shall mean the Board of Directors of the
         Company.

                           "Cause" for termination by the Company of the
         Executive's employment, after any Change in Control, shall mean (i) the
         willful and continued failure by the Executive to
<PAGE>   7
                                       -7-


         substantially perform the Executive's duties with the Company (other
         than any such failure resulting from the Executive's incapacity due to
         physical or mental illness or any such actual or anticipated failure
         after the issuance of a Notice of Termination for Good Reason by the
         Executive) after a written demand for substantial performance is
         delivered to the Executive by the Board, which demand specifically
         identifies the manner in which the Board believes that the Executive
         has not substantially performed the Executive's duties, or (ii) the
         willful engaging by the Executive in gross misconduct which is
         demonstrably and materially injurious to the Company or any of its
         subsidiaries, monetarily or otherwise. No act, or failure to act, on
         the Executive's part shall be deemed "willful" unless done, or omitted
         to be done, by the Executive not in good faith and without reasonable
         belief that the Executive's act, or failure to act, was in the best
         interest of the Company.

                  A "Change in Control" shall be deemed to have occurred if the
         conditions set forth in any one of the following paragraphs shall have
         been satisfied:

                           (a) Continuing Directors constitute two-thirds or
                  less of the membership of the Board, whether as the result of
                  a proxy contest or for any other reason or reasons; or

                           (b) Any Person is or becomes the Beneficial owner,
                  directly or indirectly, of securities of the Company
                  representing twenty-five percent or more of the combined
                  voting power of the Company's then outstanding voting
                  securities; or

                           (c) There is a change in control of the Company of a
                  nature that would be required to be reported on Form 8-K or
                  item 6(e) of Schedule 14A of Regulation 14A or any similar
                  item, schedule or form under the Exchange Act, as in effect at
                  the time of the change, whether or not the Company is then
                  subject to such reporting requirement, including without
                  limitation any merger or consolidation of the Company with any
                  other corporation, other than (i) a merger or consolidation
                  which would result in the voting securities of the Company
                  outstanding immediately prior thereto continuing to represent
                  (either by remaining outstanding or by being converted into
                  voting securities of the surviving or parent entity) fifty-one
                  percent or more of the combined voting power of the voting
                  securities (entitled to vote generally for the
<PAGE>   8
                                       -8-


                  election of directors) of the Company or such surviving or
                  parent entity outstanding immediately after such merger or
                  consolidation and which would result in those persons who are
                  Continuing Directors immediately prior to such merger or
                  consolidation constituting more than two-thirds of the
                  membership of the Board or the board of such surviving or
                  parent entity immediately after, or subsequently at any time
                  as contemplated by or as a result of, such merger or
                  consolidation or (ii) a merger or consolidation effected to
                  implement a recapitalization of the company (or similar
                  transaction) in which no Person acquired twenty-five percent
                  or more of the combined voting power of the Company's then
                  outstanding securities; or

                           (d) the stockholders of the Company approve a plan of
                  complete liquidation of the Company or an agreement for the
                  sale or disposition by the Company of all or substantially all
                  of the Company's assets (or any transaction having a similar
                  effect).

         "Code" shall mean the Internal Revenue Code of 1986, as amended from
time to time.

         "Company" shall mean Aspen Technology, Inc. and any successor to its
business and/or assets which assumes or agrees to perform this Agreement, by
operation of law or otherwise.

         "Compensation Committee" shall mean the Compensation and Nominating
Committee of the Board.

         "Continuing Director" shall mean any director (i) who has continuously
been a member of the Board since not later than the date of a Potential Change
in Control or (ii) who is a successor of a director described in clause (i), if
such successor (and any intervening successor) shall have been recommended or
elected to succeed a Continuing Director by a majority of the then Continuing
Directors.

         "Date of Termination" shall have the meaning stated in Section 5.2
hereof.

         "Exchange Act" shall mean the Securities Exchange Act of 1934, as
amended from time to time.

         "Excise Tax" shall mean the tax imposed by Section 4999 of the
Code.

<PAGE>   9
                                       -9-


         "Executive" shall mean the individual named in the first paragraph of
this Agreement.

         "Good Reason" for termination by the Executive of the Executive's
employment shall mean the occurrence (without the Executive's express written
consent) of any one of the following acts or failures to act by the Company
unless, in the case of any act or failure to act described in paragraph (a),
(e), (f) or (g) below, such act or failure to act is corrected prior to the Date
of Termination specified in the Notice of Termination given in respect thereof
or, in the case of paragraph (c) below, such act is not objected to in writing
by the Executive within four months after notification by the Company to the
Executive of the Company's intention to take the action contemplated by such
paragraph (c):

                           (a) the assignment to the Executive of any duties
                  inconsistent with the Executive's status as a senior executive
                  officer of the Company or a meaningful alteration, adverse to
                  the Executive, in the nature or status of the Executive's
                  responsibilities (other than reporting responsibilities) from
                  those in effect immediately prior to the Change in Control;

                           (b) a reduction by the Company in the Executive's
                  annual base salary as in effect on the date hereof or as the
                  same may be increased from time to time except for
                  across-the-board salary reductions similarly affecting all
                  senior executives of the Company and all senior executives of
                  any Person in control of the Company;

                           (c) the Company's requiring the Executive to be based
                  anywhere other than the Boston Metropolitan Area (or, if
                  different, the metropolitan area in which the Company's
                  principal executive offices are located immediately prior to
                  the Change in Control) except for required travel on the
                  Company business to an extent substantially consistent with
                  the Executive's present business travel obligations;

                           (d) the failure by the Company, without the
                  Executive's consent, to pay to the Executive any portion of
                  the Executive's current compensation, or to pay to the
                  Executive any portion of an installment of deferred
                  compensation under any deferred compensation program of the
                  Company, within fourteen days of the date such compensation is
                  due;

                           (e) the failure by the Company to continue in effect
                  any compensation plan in which the Executive participates
<PAGE>   10
                                      -10-


                  immediately prior to the Change in Control which is material
                  to the Executive's total compensation, or the failure by the
                  Company to continue the Executive's participation therein on a
                  basis not materially less favorable, both in terms of the
                  amount of benefits provided and the level of the Executive's
                  participation relative to other participants, as existed at
                  the time of the Change in Control;

                           (f) the failure by the Company to continue to provide
                  the Executive with benefits substantially similar to those
                  enjoyed by the Executive under any of the Company' s pension,
                  life insurance, medical, health and accident, or disability
                  plans in which the Executive was participating at the time of
                  the Change in Control, the taking of any action by the Company
                  which would directly or indirectly materially reduce any of
                  such benefits or deprive the Executive of any material fringe
                  benefit enjoyed by the Executive at the time of the Change in
                  Control, or the failure by the Company to provide the
                  Executive with the number of paid vacation days to which the
                  Executive is entitled on the basis of years of service with
                  the Company in accordance with the Company's normal vacation
                  policy in effect at the time of the Change in Control; or

                           (g) any purported termination of the Executive's
                  employment which is not effected pursuant to a Notice of
                  Termination satisfying the requirements of Section 5.1.

         "Notice of Termination" shall have the meaning stated in Section
5.1.

         "Person" shall have the meaning given in Section 3(a)(9) of the
Exchange Act, as modified and used in Sections 13(d) and 14(d). thereof;
however, a Person shall not include (i) the Company or any of its subsidiaries,
(ii) a trustee or other fiduciary holding securities under an employee benefit
plan of the Company or any of its subsidiaries, (iii) an underwriter temporarily
holding securities pursuant to a registered offering of such securities in
accordance with an agreement with the Company, or (iv) a corporation owned,
directly or indirectly, by the stockholders of the Company in substantially the
same proportions as their ownership of stock of the Company.

         "Potential Change in Control" shall be deemed to have occurred if the
conditions set forth in any one of the following paragraphs shall have been
satisfied:

<PAGE>   11
                                      -11-

                           (a) the Company enters into an agreement, the
                  consummation of which would result in the occurrence of a
                  Change in Control;

                           (b)      the Company or any Person publicly announces
                  an intention to take or to consider taking actions which, if
                  consummated, would constitute a Change in Control;

                           (c) any Person becomes the Beneficial Owner, directly
                  or indirectly, of securities of the Company representing
                  fifteen percent or more of the combined voting power of the
                  Company's then outstanding securities (entitled to vote
                  generally for the election of directors); or

                           (d) the Board adopts a resolution to the effect that,
                  for purposes of this Agreement, a Potential Change in Control
                  has occurred.

         "Severance Payments" shall mean those payments described in Section 3.2
hereof.

         "Total Payments" shall mean those payments described in Section 4
hereof.

         IN WITNESS WHEREOF, the Company and the Executive have executed and
delivered this Agreement on the date first written above.




                                            ASPEN TECHNOLOGY, INC.




                                            By:
                                               ---------------------------------





                                               ---------------------------------
                                                      Joseph F. Boston


<PAGE>   1
                                                                   Exhibit 10.26


                           CHANGE IN CONTROL AGREEMENT

         AGREEMENT dated as of August 12, 1997 by and between Aspen Technology,
Inc., a Massachusetts corporation (the "Company"), and David L. McQuillin (the
"Executive").

         WHEREAS, the Company considers it essential to the best interests of
its stockholders to foster the continuous employment of key management
personnel; and

         WHEREAS, the Company has determined that appropriate steps should be
taken to reinforce and encourage the continued attention and dedication of
members of the Company's management, including the Executive, to their assigned
duties with the Company without distraction in the face of potentially
disturbing circumstances arising from the possibility of a Change in Control (as
defined herein);

         NOW THEREFORE, in consideration of the premises and the mutual
covenants herein contained, and for other valuable consideration, the Company
and the Executive hereby agree as follows:

         1. Defined Terms. The definitions of capitalized terms used in this
Agreement are provided in the last section hereof.

         2. Term of Agreement. This Agreement shall commence on the date hereof
and shall continue in effect through June 30, 2002. Thereafter, this Agreement
shall be automatically renewed for successive one year terms unless the Company
sends written notice of termination to the Executive at least 60 days before the
expiration date of this Agreement, which termination will be effective at that
expiration date. If a Change in Control shall have occurred during the term of
this Agreement, however, this Agreement shall continue in effect for a period of
three years beyond the last day of the month in which the Change in Control
occurred. Notwithstanding the foregoing provisions of this Section 2, this
Agreement shall terminate, unless earlier terminated in accordance with this
Agreement, (i) one year after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee, upon recommendation of the
Company's chief executive officer, has voted to terminate this Agreement or (ii)
if earlier, immediately after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee has determined that the
Executive's level of responsibility (other than reporting responsibility) has
substantially changed from the Executive's current level of responsibility,

<PAGE>   2
                                      -2-


in either case only if the notification occurs prior to a Potential Change in
Control that results in a Change in Control.

         3. Payments After Change in Control.

         3.1 If the Executive's employment shall be terminated for any reason
following a Change in Control and during the term of this Agreement, the Company
shall pay the Executive's full salary to the Executive through the Date of
Termination at the rate in effect at the time the Notice of Termination is
given, together with all compensation and benefits payable to the Executive
through the Date of Termination under the terms of any compensation or benefit
plan, program or arrangement maintained by the Company during such period.

         3.2 Subject to Section 3.3, the Company shall pay to the Executive the
payments described in this Section 3.2 (the "Severance Payments") upon the
termination of the Executive's employment following a Change in Control and
during the term of this Agreement, in addition to the payments and benefits
described in Section 3.1, unless such termination is (i) by the Company for
Cause, (ii) by reason of death, (iii) by the Executive without Good Reason, or
(iv) after the Executive shall have attained age 70. In lieu of any further
salary payments to the Executive for periods subsequent to the Date of
Termination and in lieu of any severance benefits otherwise payable to the
Executive under any then existing broad-based employee severance plan, the
Company shall pay to the Executive a lump sum severance payment, in cash, equal
to three times the sum of (x) the higher of the Executive's annual base salary
in effect immediately prior to the occurrence of the event or circumstance upon
which the Notice of Termination is based or in effect immediately prior to the
Change in Control and (y) the higher of the average of the annual bonuses paid
to the Executive for the three years (or the number of years employed, if less)
immediately preceding the occurrence of the event or circumstance upon which the
Notice of Termination is based or the Change in Control. In lieu of any further
life, disability, accident and health insurance benefits otherwise due to the
Executive, the Company shall pay to the Executive a lump sum amount, in cash,
equal to the cost to the Company (as determined by the Company in good faith
with reference to its most recent actual experience) of providing such benefits,
to the extent that the Executive is eligible to receive such benefits
immediately prior to the Notice of Termination, for a period of three years
commencing on the Date of Termination.

         3.3 The payments provided for in Section 3.2 shall be made not later
than the fifth day following the Date of Termination.
<PAGE>   3
                                      -3-


         3.4 The Company also shall pay to the Executive all legal fees and
expenses incurred by the Executive in seeking to obtain or enforce any benefit
or right provided by this Agreement, payable within five business days after
delivery of the Executive's written requests for payment accompanied with such
evidence of fees and expenses incurred as the Company reasonably may require.

         4. Certain Additional Payments by the Company.

         4.1 Notwithstanding any other provisions of this Agreement, in the
event that any payment or benefit received or to be received by the Executive in
connection with a Change in Control or the termination of the Executive's
employment (all such payments and benefits, including the Severance Payments,
the "Total Payments") is determined to be subject (in whole or part) to the
Excise Tax, then the Executive shall be entitled to receive an additional
payment (a "Gross-Up Payment") in an amount such that after payment by the
Executive of all taxes (including any interest or penalties imposed with respect
to such taxes), including without limitation any income taxes and Excise Tax
imposed upon the Gross-Up Payment, the Executive retains an amount equal to the
Total Payments. Notwithstanding the foregoing provisions of this Section 4.1, if
it shall be determined that the Executive is entitled to a Gross-Up Payment, but
that the Total Payments do not exceed 110% of the greatest amount (the "Reduced
Amount") that could be paid to the Executive such that the receipt thereof would
not give rise to any Excise Tax, then no Gross-Up Payment shall be made to the
Executive and the Total Payments shall be reduced to the Reduced Amount.

         4.2 All determinations required to be made under this Section 4,
including whether and when a Gross-Up Payment is required and the amount of such
Gross-Up Payment and the assumptions to be utilized in arriving at such
determination, shall be made by the Company's accountants or such other
certified public accounting firm reasonably acceptable to the Company as may be
designated by the Executive (the "Accounting Firm") which shall provide detailed
supporting calculations both to the Company and the Executive.

         5. Termination Procedures.

         5.1 Notice of Termination. After a Change in Control and during the
term of this Agreement, any purported termination of the Executive's employment
(other than by reason of death) shall be communicated by written Notice of
Termination from one party hereto to the other party hereto in accordance with
Section 8. Further, a Notice of Termination for Cause is required to include a
copy of a resolution duly adopted by the

<PAGE>   4
                                      -4-


affirmative vote of not less than three-quarters of the entire membership of the
Board at a meeting of the Board which was called and held for the purpose of
considering such termination (after reasonable notice to the Executive and an
opportunity for the Executive, together with the Executive's counsel, to be
heard before the Board) finding that, in the good faith opinion of the Board,
the Executive was guilty of conduct set forth in the definition of Cause.

         5.2 Date of Termination. "Date of Termination", with respect to any
purported termination of the Executive's employment after a Change in Control
and during the term of this Agreement, shall mean the date specified in the
Notice of Termination (which, in the case of a termination by the Company
otherwise than for Cause, shall not be less than thirty days and, in the case of
a termination by the Executive, shall not be less than fifteen days nor more
than sixty days, respectively, from the date such Notice of Termination is
given).

         6. No Mitigation. If the Executive's employment by the Company is
terminated during the term of this Agreement, the Executive is not required to
seek other employment or to attempt in any way to reduce any amounts payable to
the Executive by the Company pursuant to Section 3. Further, the amount of any
payment or benefit provided for in Section 3 shall not be reduced by any
compensation earned by the Executive as the result of employment by another
employer, by retirement benefits, by offset against any amount claimed to be
owed by the Executive to the Company, or otherwise.

         7. Executive's Covenants. The Executive agrees that, subject to the
terms and conditions of this Agreement, in the event of a Potential Change in
Control during the term of this Agreement, the Executive will remain in the
employ of the Company until the earliest of (i) a date which is six months from
the date of such Potential Change of Control, (ii) the date of a Change in
Control, (iii) the date of termination by the Executive of the Executive's
employment for Good Reason (determined by treating the Potential Change in
Control as a Change in Control in applying the definition of Good Reason), by
reason of death or Retirement; or (iv) the termination by the Company of the
Executive's employment for any reason.

         8. Successors; Binding Agreement.

         8.1 In addition to any obligations imposed by law upon any successor to
the Company, the Company will require any successor (whether direct or indirect,
by purchase, merger, consolidation or otherwise) to all or substantially all of
the business and/or assets of the

<PAGE>   5
                                      -5-


Company to expressly assume and agree to perform this Agreement in the same
manner and to the same extent that the Company would be required to perform it
if no such succession had taken place. Failure of the Company to obtain such
assumption and agreement prior to the effectiveness of any such succession shall
be a breach of this Agreement and shall entitle the Executive to compensation
from the Company in the same amount and on the same terms as the Executive would
be entitled to hereunder if the Executive were to terminate the Executive's
employment for Good Reason after a Change in Control, except that, for purposes
of implementing the foregoing, the date on which any such succession becomes
effective shall be deemed the Date of Termination.

         8.2 This Agreement shall inure to the benefit of and be enforceable by
the Executive's personal or legal representatives. If the Executive shall die
while any amount would still be payable to the Executive hereunder (other than
amounts which, by their terms, terminate upon the death of the Executive) if the
Executive had continued to live, all such amounts, unless otherwise provided
herein, shall be paid in accordance with the terms of this Agreement to the
Executive's representatives.

         9. Notices. For the purpose of this Agreement, notices and all other
communications provided for in the Agreement shall be in writing and shall be
deemed to have been duly given when delivered or mailed by United States
certified or registered mail, return receipt requested, postage prepaid,
addressed to the respective addresses set forth below, or to such other address
as either party may have furnished to the other in writing in accordance
herewith, except that notice of change of address shall be effective only upon
actual receipt:

                           To the Company:
                           Aspen Technology, Inc.
                           Ten Canal Park
                           Cambridge, MA  02141

                           Attention:  General Counsel

                           To the Executive:
                           David L. McQuillin
                           2017 Kinderton Manor Drive
                           Duluth, GA  30155

         10. Miscellaneous. No provision of this Agreement may be modified,
waived or discharged unless such waiver, modification or

<PAGE>   6
                                      -6-


discharge is agreed to in writing and signed by the Executive and such officer
as may be specifically designated by the Board. Except as expressly provided
herein, no waiver by either party hereto at any time of any breach by the other
party hereto of, or compliance with, any condition or provision of this
Agreement to be performed by such other party shall be deemed a waiver of
similar or dissimilar provisions or conditions at the same or at any prior or
subsequent time. No agreements or representations, oral or otherwise, express or
implied, with respect to the subject matter hereof have been made by either
party which are not expressly set forth in this Agreement. The validity,
interpretation, construction and performance of this Agreement shall be governed
by the laws of the Commonwealth of Massachusetts, and this Agreement shall be an
instrument under seal. All references to sections of the Exchange Act or the
Code shall be deemed also to refer to any successor provisions to such sections.
Any payments provided for hereunder shall be paid net of any applicable
withholding required under federal, state or local law and any additional
withholding to which the Executive has agreed.

         11. Settlement of Disputes; Arbitration. All claims by the Executive
for benefits under this Agreement shall be directed to and determined by the
Board and shall be in writing. Any denial by the Board of a claim for benefits
under this Agreement shall be delivered to the Executive in writing and shall
set forth the specific reasons for the denial and the specific provisions of
this Agreement relied upon. Any further dispute or controversy arising under or
in connection with this Agreement shall be settled exclusively by arbitration in
Boston, Massachusetts, in accordance with the rules of the American Arbitration
Association then in effect. Judgment may be entered on the arbitrator' s award
in any court having jurisdiction. The Executive shall, however, be entitled to
seek specific performance of the Executive's right to be paid until the Date of
Termination during the pendency of any dispute or controversy arising under or
in connection with this Agreement.

         12. Definitions. For purposes of this Agreement, the following terms
shall have the-meanings indicated below:

                  "Beneficial owner" shall have the meaning defined in Rule
         13d-3 under the Exchange Act.

                  "Board" shall mean the Board of Directors of the Company.

                  "Cause" for termination by the Company of the Executive's
         employment, after any Change in Control, shall mean (i) the willful and
         continued failure by the Executive to

<PAGE>   7
                                      -7-


         substantially perform the Executive's duties with the Company (other
         than any such failure resulting from the Executive's incapacity due to
         physical or mental illness or any such actual or anticipated failure
         after the issuance of a Notice of Termination for Good Reason by the
         Executive) after a written demand for substantial performance is
         delivered to the Executive by the Board, which demand specifically
         identifies the manner in which the Board believes that the Executive
         has not substantially performed the Executive's duties, or (ii) the
         willful engaging by the Executive in gross misconduct which is
         demonstrably and materially injurious to the Company or any of its
         subsidiaries, monetarily or otherwise. No act, or failure to act, on
         the Executive's part shall be deemed "willful" unless done, or omitted
         to be done, by the Executive not in good faith and without reasonable
         belief that the Executive's act, or failure to act, was in the best
         interest of the Company.

                  A "Change in Control" shall be deemed to have occurred if the
         conditions set forth in any one of the following paragraphs shall have
         been satisfied:

                           (a) Continuing Directors constitute two-thirds or
                  less of the membership of the Board, whether as the result of
                  a proxy contest or for any other reason or reasons; or

                           (b) Any Person is or becomes the Beneficial owner,
                  directly or indirectly, of securities of the Company
                  representing twenty-five percent or more of the combined
                  voting power of the Company's then outstanding voting
                  securities; or

                           (c) There is a change in control of the Company of a
                  nature that would be required to be reported on Form 8-K or
                  item 6(e) of Schedule 14A of Regulation 14A or any similar
                  item, schedule or form under the Exchange Act, as in effect at
                  the time of the change, whether or not the Company is then
                  subject to such reporting requirement, including without
                  limitation any merger or consolidation of the Company with any
                  other corporation, other than (i) a merger or consolidation
                  which would result in the voting securities of the Company
                  outstanding immediately prior thereto continuing to represent
                  (either by remaining outstanding or by being converted into
                  voting securities of the surviving or parent entity) fifty-one
                  percent or more of the combined voting power of the voting
                  securities (entitled to vote generally for the

<PAGE>   8
                                      -8-


                  election of directors) of the Company or such surviving or
                  parent entity outstanding immediately after such merger or
                  consolidation and which would result in those persons who are
                  Continuing Directors immediately prior to such merger or
                  consolidation constituting more than two-thirds of the
                  membership of the Board or the board of such surviving or
                  parent entity immediately after, or subsequently at any time
                  as contemplated by or as a result of, such merger or
                  consolidation or (ii) a merger or consolidation effected to
                  implement a recapitalization of the company (or similar
                  transaction) in which no Person acquired twenty-five percent
                  or more of the combined voting power of the Company's then
                  outstanding securities; or

                           (d) the stockholders of the Company approve a plan of
                  complete liquidation of the Company or an agreement for the
                  sale or disposition by the Company of all or substantially all
                  of the Company's assets (or any transaction having a similar
                  effect).

         "Code" shall mean the Internal Revenue Code of 1986, as amended from
time to time.

         "Company" shall mean Aspen Technology, Inc. and any successor to its
business and/or assets which assumes or agrees to perform this Agreement, by
operation of law or otherwise.

         "Compensation Committee" shall mean the Compensation and Nominating
Committee of the Board.

         "Continuing Director" shall mean any director (i) who has continuously
been a member of the Board since not later than the date of a Potential Change
in Control or (ii) who is a successor of a director described in clause (i), if
such successor (and any intervening successor) shall have been recommended or
elected to succeed a Continuing Director by a majority of the then Continuing
Directors.

         "Date of Termination" shall have the meaning stated in Section 5.2
hereof.

         "Exchange Act" shall mean the Securities Exchange Act of 1934, as
amended from time to time.

         "Excise Tax" shall mean the tax imposed by Section 4999 of the Code.
<PAGE>   9
                                      -9-


         "Executive" shall mean the individual named in the first paragraph of
this Agreement.

         "Good Reason" for termination by the Executive of the Executive's
employment shall mean the occurrence (without the Executive's express written
consent) of any one of the following acts or failures to act by the Company
unless, in the case of any act or failure to act described in paragraph (a),
(e), (f) or (g) below, such act or failure to act is corrected prior to the Date
of Termination specified in the Notice of Termination given in respect thereof
or, in the case of paragraph (c) below, such act is not objected to in writing
by the Executive within four months after notification by the Company to the
Executive of the Company's intention to take the action contemplated by such
paragraph (c):

                           (a) the assignment to the Executive of any duties
                  inconsistent with the Executive's status as a senior executive
                  officer of the Company or a meaningful alteration, adverse to
                  the Executive, in the nature or status of the Executive's
                  responsibilities (other than reporting responsibilities) from
                  those in effect immediately prior to the Change in Control;

                           (b) a reduction by the Company in the Executive's
                  annual base salary as in effect on the date hereof or as the
                  same may be increased from time to time except for
                  across-the-board salary reductions similarly affecting all
                  senior executives of the Company and all senior executives of
                  any Person in control of the Company;

                           (c) the Company's requiring the Executive to be based
                  anywhere other than the Boston Metropolitan Area (or, if
                  different, the metropolitan area in which the Company's
                  principal executive offices are located immediately prior to
                  the Change in Control) except for required travel on the
                  Company business to an extent substantially consistent with
                  the Executive's present business travel obligations;

                           (d) the failure by the Company, without the
                  Executive's consent, to pay to the Executive any portion of
                  the Executive's current compensation, or to pay to the
                  Executive any portion of an installment of deferred
                  compensation under any deferred compensation program of the
                  Company, within fourteen days of the date such compensation is
                  due;

                           (e) the failure by the Company to continue in effect
                  any compensation plan in which the Executive participates

<PAGE>   10
                                      -10-


                  immediately prior to the Change in Control which is material
                  to the Executive's total compensation, or the failure by the
                  Company to continue the Executive's participation therein on a
                  basis not materially less favorable, both in terms of the
                  amount of benefits provided and the level of the Executive's
                  participation relative to other participants, as existed at
                  the time of the Change in Control;

                           (f) the failure by the Company to continue to provide
                  the Executive with benefits substantially similar to those
                  enjoyed by the Executive under any of the Company' s pension,
                  life insurance, medical, health and accident, or disability
                  plans in which the Executive was participating at the time of
                  the Change in Control, the taking of any action by the Company
                  which would directly or indirectly materially reduce any of
                  such benefits or deprive the Executive of any material fringe
                  benefit enjoyed by the Executive at the time of the Change in
                  Control, or the failure by the Company to provide the
                  Executive with the number of paid vacation days to which the
                  Executive is entitled on the basis of years of service with
                  the Company in accordance with the Company's normal vacation
                  policy in effect at the time of the Change in Control; or

                           (g) any purported termination of the Executive's
                  employment which is not effected pursuant to a Notice of
                  Termination satisfying the requirements of Section 5.1.

         "Notice of Termination" shall have the meaning stated in Section 5.1.

         "Person" shall have the meaning given in Section 3(a)(9) of the
Exchange Act, as modified and used in Sections 13(d) and 14(d). thereof;
however, a Person shall not include (i) the Company or any of its subsidiaries,
(ii) a trustee or other fiduciary holding securities under an employee benefit
plan of the Company or any of its subsidiaries, (iii) an underwriter temporarily
holding securities pursuant to a registered offering of such securities in
accordance with an agreement with the Company, or (iv) a corporation owned,
directly or indirectly, by the stockholders of the Company in substantially the
same proportions as their ownership of stock of the Company.

         "Potential Change in Control" shall be deemed to have occurred if the
conditions set forth in any one of the following paragraphs shall have been
satisfied:
<PAGE>   11
                                      -11-


                           (a) the Company enters into an agreement, the
                  consummation of which would result in the occurrence of a
                  Change in Control;

                           (b) the Company or any Person publicly announces an
                  intention to take or to consider taking actions which, if
                  consummated, would constitute a Change in Control;

                           (c) any Person becomes the Beneficial Owner, directly
                  or indirectly, of securities of the Company representing
                  fifteen percent or more of the combined voting power of the
                  Company's then outstanding securities (entitled to vote
                  generally for the election of directors); or

                           (d) the Board adopts a resolution to the effect that,
                  for purposes of this Agreement, a Potential Change in Control
                  has occurred.

         "Severance Payments" shall mean those payments described in Section 3.2
hereof.

         "Total Payments" shall mean those payments described in Section 4
hereof.

         IN WITNESS WHEREOF, the Company and the Executive have executed and
delivered this Agreement on the date first written above.



                                     ASPEN TECHNOLOGY, INC.



                                     By:_______________________________________



                                        ________________________________________
                                                 David L. McQuillin

<PAGE>   1
                                                                   EXHIBIT 10.27




                           CHANGE IN CONTROL AGREEMENT

      AGREEMENT dated as of August 12, 1997 by and between Aspen Technology,
Inc., a Massachusetts corporation (the "Company"), and Mary A. Palermo (the
"Executive").

      WHEREAS, the Company considers it essential to the best interests of its
stockholders to foster the continuous employment of key management personnel;
and

      WHEREAS, the Company has determined that appropriate steps should be taken
to reinforce and encourage the continued attention and dedication of members of
the Company's management, including the Executive, to their assigned duties with
the Company without distraction in the face of potentially disturbing
circumstances arising from the possibility of a Change in Control (as defined
herein);

      NOW THEREFORE, in consideration of the premises and the mutual covenants
herein contained, and for other valuable consideration, the Company and the
Executive hereby agree as follows:

      1. Defined Terms. The definitions of capitalized terms used in this
Agreement are provided in the last section hereof.

      2. Term of Agreement. This Agreement shall commence on the date hereof and
shall continue in effect through June 30, 2002. Thereafter, this Agreement shall
be automatically renewed for successive one year terms unless the Company sends
written notice of termination to the Executive at least 60 days before the
expiration date of this Agreement, which termination will be effective at that
expiration date. If a Change in Control shall have occurred during the term of
this Agreement, however, this Agreement shall continue in effect for a period of
three years beyond the last day of the month in which the Change in Control
occurred. Notwithstanding the foregoing provisions of this Section 2, this
Agreement shall terminate, unless earlier terminated in accordance with this
Agreement, (i) one year after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee, upon recommendation of the
Company's chief executive officer, has voted to terminate this Agreement or (ii)
if earlier, immediately after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee has determined that the
Executive's level of responsibility (other than reporting responsibility) has
substantially changed from the Executive's current level of responsibility,
<PAGE>   2
                                      -2-


in either case only if the notification occurs prior to a Potential Change in
Control that results in a Change in Control.

      3. Payments After Change in Control.

      3.1 If the Executive's employment shall be terminated for any reason
following a Change in Control and during the term of this Agreement, the Company
shall pay the Executive's full salary to the Executive through the Date of
Termination at the rate in effect at the time the Notice of Termination is
given, together with all compensation and benefits payable to the Executive
through the Date of Termination under the terms of any compensation or benefit
plan, program or arrangement maintained by the Company during such period.

      3.2 Subject to Section 3.3, the Company shall pay to the Executive the
payments described in this Section 3.2 (the "Severance Payments") upon the
termination of the Executive's employment following a Change in Control and
during the term of this Agreement, in addition to the payments and benefits
described in Section 3.1, unless such termination is (i) by the Company for
Cause, (ii) by reason of death, (iii) by the Executive without Good Reason, or
(iv) after the Executive shall have attained age 70. In lieu of any further
salary payments to the Executive for periods subsequent to the Date of
Termination and in lieu of any severance benefits otherwise payable to the
Executive under any then existing broad-based employee severance plan, the
Company shall pay to the Executive a lump sum severance payment, in cash, equal
to three times the sum of (x) the higher of the Executive's annual base salary
in effect immediately prior to the occurrence of the event or circumstance upon
which the Notice of Termination is based or in effect immediately prior to the
Change in Control and (y) the higher of the average of the annual bonuses paid
to the Executive for the three years (or the number of years employed, if less)
immediately preceding the occurrence of the event or circumstance upon which the
Notice of Termination is based or the Change in Control. In lieu of any further
life, disability, accident and health insurance benefits otherwise due to the
Executive, the Company shall pay to the Executive a lump sum amount, in cash,
equal to the cost to the Company (as determined by the Company in good faith
with reference to its most recent actual experience) of providing such benefits,
to the extent that the Executive is eligible to receive such benefits
immediately prior to the Notice of Termination, for a period of three years
commencing on the Date of Termination.

      3.3 The payments provided for in Section 3.2 shall be made not later than
the fifth day following the Date of Termination.
<PAGE>   3
                                      -3-


      3.4 The Company also shall pay to the Executive all legal fees and
expenses incurred by the Executive in seeking to obtain or enforce any benefit
or right provided by this Agreement, payable within five business days after
delivery of the Executive's written requests for payment accompanied with such
evidence of fees and expenses incurred as the Company reasonably may require.

      4. Certain Additional Payments by the Company.

      4.1 Notwithstanding any other provisions of this Agreement, in the event
that any payment or benefit received or to be received by the Executive in
connection with a Change in Control or the termination of the Executive's
employment (all such payments and benefits, including the Severance Payments,
the "Total Payments") is determined to be subject (in whole or part) to the
Excise Tax, then the Executive shall be entitled to receive an additional
payment (a "Gross-Up Payment") in an amount such that after payment by the
Executive of all taxes (including any interest or penalties imposed with respect
to such taxes), including without limitation any income taxes and Excise Tax
imposed upon the Gross-Up Payment, the Executive retains an amount equal to the
Total Payments. Notwithstanding the foregoing provisions of this Section 4.1, if
it shall be determined that the Executive is entitled to a Gross-Up Payment, but
that the Total Payments do not exceed 110% of the greatest amount (the "Reduced
Amount") that could be paid to the Executive such that the receipt thereof would
not give rise to any Excise Tax, then no Gross-Up Payment shall be made to the
Executive and the Total Payments shall be reduced to the Reduced Amount.

      4.2 All determinations required to be made under this Section 4, including
whether and when a Gross-Up Payment is required and the amount of such Gross-Up
Payment and the assumptions to be utilized in arriving at such determination,
shall be made by the Company's accountants or such other certified public
accounting firm reasonably acceptable to the Company as may be designated by the
Executive (the "Accounting Firm") which shall provide detailed supporting
calculations both to the Company and the Executive.

      5. Termination Procedures.

      5.1 Notice of Termination. After a Change in Control and during the term
of this Agreement, any purported termination of the Executive's employment
(other than by reason of death) shall be communicated by written Notice of
Termination from one party hereto to the other party hereto in accordance with
Section 8. Further, a Notice of Termination for Cause is required to include a
copy of a resolution duly adopted by the
<PAGE>   4
                                      -4-


affirmative vote of not less than three-quarters of the entire membership of the
Board at a meeting of the Board which was called and held for the purpose of
considering such termination (after reasonable notice to the Executive and an
opportunity for the Executive, together with the Executive's counsel, to be
heard before the Board) finding that, in the good faith opinion of the Board,
the Executive was guilty of conduct set forth in the definition of Cause.

      5.2 Date of Termination. "Date of Termination", with respect to any
purported termination of the Executive's employment after a Change in Control
and during the term of this Agreement, shall mean the date specified in the
Notice of Termination (which, in the case of a termination by the Company
otherwise than for Cause, shall not be less than thirty days and, in the case of
a termination by the Executive, shall not be less than fifteen days nor more
than sixty days, respectively, from the date such Notice of Termination is
given).

      6. No Mitigation. If the Executive's employment by the Company is
terminated during the term of this Agreement, the Executive is not required to
seek other employment or to attempt in any way to reduce any amounts payable to
the Executive by the Company pursuant to Section 3. Further, the amount of any
payment or benefit provided for in Section 3 shall not be reduced by any
compensation earned by the Executive as the result of employment by another
employer, by retirement benefits, by offset against any amount claimed to be
owed by the Executive to the Company, or otherwise.

      7. Executive's Covenants. The Executive agrees that, subject to the terms
and conditions of this Agreement, in the event of a Potential Change in Control
during the term of this Agreement, the Executive will remain in the employ of
the Company until the earliest of (i) a date which is six months from the date
of such Potential Change of Control, (ii) the date of a Change in Control, (iii)
the date of termination by the Executive of the Executive's employment for Good
Reason (determined by treating the Potential Change in Control as a Change in
Control in applying the definition of Good Reason), by reason of death or
Retirement; or (iv) the termination by the Company of the Executive's employment
for any reason.

      8. Successors; Binding Agreement.

      8.1 In addition to any obligations imposed by law upon any successor to
the Company, the Company will require any successor (whether direct or indirect,
by purchase, merger, consolidation or otherwise) to all or substantially all of
the business and/or assets of the
<PAGE>   5
                                      -5-


Company to expressly assume and agree to perform this Agreement in the same
manner and to the same extent that the Company would be required to perform it
if no such succession had taken place. Failure of the Company to obtain such
assumption and agreement prior to the effectiveness of any such succession shall
be a breach of this Agreement and shall entitle the Executive to compensation
from the Company in the same amount and on the same terms as the Executive would
be entitled to hereunder if the Executive were to terminate the Executive's
employment for Good Reason after a Change in Control, except that, for purposes
of implementing the foregoing, the date on which any such succession becomes
effective shall be deemed the Date of Termination.

      8.2 This Agreement shall inure to the benefit of and be enforceable by the
Executive's personal or legal representatives. If the Executive shall die while
any amount would still be payable to the Executive hereunder (other than amounts
which, by their terms, terminate upon the death of the Executive) if the
Executive had continued to live, all such amounts, unless otherwise provided
herein, shall be paid in accordance with the terms of this Agreement to the
Executive's representatives.

      9. Notices. For the purpose of this Agreement, notices and all other
communications provided for in the Agreement shall be in writing and shall be
deemed to have been duly given when delivered or mailed by United States
certified or registered mail, return receipt requested, postage prepaid,
addressed to the respective addresses set forth below, or to such other address
as either party may have furnished to the other in writing in accordance
herewith, except that notice of change of address shall be effective only upon
actual receipt:

                  To the Company:
                  Aspen Technology, Inc.
                  Ten Canal Park
                  Cambridge, MA  02141

                  Attention:  General Counsel

                  To the Executive:
                  Mary A. Palermo
                  55 Sawyer Drive
                  Dedham, MA  02026

      10. Miscellaneous. No provision of this Agreement may be modified, waived
or discharged unless such waiver, modification or
<PAGE>   6
                                      -6-


discharge is agreed to in writing and signed by the Executive and such officer
as may be specifically designated by the Board. Except as expressly provided
herein, no waiver by either party hereto at any time of any breach by the other
party hereto of, or compliance with, any condition or provision of this
Agreement to be performed by such other party shall be deemed a waiver of
similar or dissimilar provisions or conditions at the same or at any prior or
subsequent time. No agreements or representations, oral or otherwise, express or
implied, with respect to the subject matter hereof have been made by either
party which are not expressly set forth in this Agreement. The validity,
interpretation, construction and performance of this Agreement shall be governed
by the laws of the Commonwealth of Massachusetts, and this Agreement shall be an
instrument under seal. All references to sections of the Exchange Act or the
Code shall be deemed also to refer to any successor provisions to such sections.
Any payments provided for hereunder shall be paid net of any applicable
withholding required under federal, state or local law and any additional
withholding to which the Executive has agreed.

      11. Settlement of Disputes; Arbitration. All claims by the Executive for
benefits under this Agreement shall be directed to and determined by the Board
and shall be in writing. Any denial by the Board of a claim for benefits under
this Agreement shall be delivered to the Executive in writing and shall set
forth the specific reasons for the denial and the specific provisions of this
Agreement relied upon. Any further dispute or controversy arising under or in
connection with this Agreement shall be settled exclusively by arbitration in
Boston, Massachusetts, in accordance with the rules of the American Arbitration
Association then in effect. Judgment may be entered on the arbitrator' s award
in any court having jurisdiction. The Executive shall, however, be entitled to
seek specific performance of the Executive's right to be paid until the Date of
Termination during the pendency of any dispute or controversy arising under or
in connection with this Agreement.

      12. Definitions. For purposes of this Agreement, the following terms shall
have the-meanings indicated below:

                  "Beneficial owner" shall have the meaning defined in Rule
      13d-3 under the Exchange Act.

                  "Board" shall mean the Board of Directors of the Company.

                  "Cause" for termination by the Company of the Executive's
      employment, after any Change in Control, shall mean (i) the willful and
      continued failure by the Executive to
<PAGE>   7
                                      -7-


      substantially perform the Executive's duties with the Company (other than
      any such failure resulting from the Executive's incapacity due to physical
      or mental illness or any such actual or anticipated failure after the
      issuance of a Notice of Termination for Good Reason by the Executive)
      after a written demand for substantial performance is delivered to the
      Executive by the Board, which demand specifically identifies the manner in
      which the Board believes that the Executive has not substantially
      performed the Executive's duties, or (ii) the willful engaging by the
      Executive in gross misconduct which is demonstrably and materially
      injurious to the Company or any of its subsidiaries, monetarily or
      otherwise. No act, or failure to act, on the Executive's part shall be
      deemed "willful" unless done, or omitted to be done, by the Executive not
      in good faith and without reasonable belief that the Executive's act, or
      failure to act, was in the best interest of the Company.

            A "Change in Control" shall be deemed to have occurred if the
      conditions set forth in any one of the following paragraphs shall have
      been satisfied:

                  (a) Continuing Directors constitute two-thirds or less of the
            membership of the Board, whether as the result of a proxy contest or
            for any other reason or reasons; or

                  (b) Any Person is or becomes the Beneficial owner, directly or
            indirectly, of securities of the Company representing twenty-five
            percent or more of the combined voting power of the Company's then
            outstanding voting securities; or

                  (c) There is a change in control of the Company of a nature
            that would be required to be reported on Form 8-K or item 6(e) of
            Schedule 14A of Regulation 14A or any similar item, schedule or form
            under the Exchange Act, as in effect at the time of the change,
            whether or not the Company is then subject to such reporting
            requirement, including without limitation any merger or
            consolidation of the Company with any other corporation, other than
            (i) a merger or consolidation which would result in the voting
            securities of the Company outstanding immediately prior thereto
            continuing to represent (either by remaining outstanding or by being
            converted into voting securities of the surviving or parent entity)
            fifty-one percent or more of the combined voting power of the voting
            securities (entitled to vote generally for the
<PAGE>   8
                                      -8-


            election of directors) of the Company or such surviving or parent
            entity outstanding immediately after such merger or consolidation
            and which would result in those persons who are Continuing Directors
            immediately prior to such merger or consolidation constituting more
            than two-thirds of the membership of the Board or the board of such
            surviving or parent entity immediately after, or subsequently at any
            time as contemplated by or as a result of, such merger or
            consolidation or (ii) a merger or consolidation effected to
            implement a recapitalization of the company (or similar transaction)
            in which no Person acquired twenty-five percent or more of the
            combined voting power of the Company's then outstanding securities;
            or

                  (d) the stockholders of the Company approve a plan of complete
            liquidation of the Company or an agreement for the sale or
            disposition by the Company of all or substantially all of the
            Company's assets (or any transaction having a similar effect).

      "Code" shall mean the Internal Revenue Code of 1986, as amended from time
to time.

      "Company" shall mean Aspen Technology, Inc. and any successor to its
business and/or assets which assumes or agrees to perform this Agreement, by
operation of law or otherwise.

      "Compensation Committee" shall mean the Compensation and Nominating
Committee of the Board.

      "Continuing Director" shall mean any director (i) who has continuously
been a member of the Board since not later than the date of a Potential Change
in Control or (ii) who is a successor of a director described in clause (i), if
such successor (and any intervening successor) shall have been recommended or
elected to succeed a Continuing Director by a majority of the then Continuing
Directors.

      "Date of Termination" shall have the meaning stated in Section 5.2 hereof.

      "Exchange Act" shall mean the Securities Exchange Act of 1934, as amended
from time to time.

      "Excise Tax" shall mean the tax imposed by Section 4999 of the Code.
<PAGE>   9
                                      -9-


      "Executive" shall mean the individual named in the first paragraph of this
Agreement.

      "Good Reason" for termination by the Executive of the Executive's
employment shall mean the occurrence (without the Executive's express written
consent) of any one of the following acts or failures to act by the Company
unless, in the case of any act or failure to act described in paragraph (a),
(e), (f) or (g) below, such act or failure to act is corrected prior to the Date
of Termination specified in the Notice of Termination given in respect thereof
or, in the case of paragraph (c) below, such act is not objected to in writing
by the Executive within four months after notification by the Company to the
Executive of the Company's intention to take the action contemplated by such
paragraph (c):

                  (a) the assignment to the Executive of any duties inconsistent
            with the Executive's status as a senior executive officer of the
            Company or a meaningful alteration, adverse to the Executive, in the
            nature or status of the Executive's responsibilities (other than
            reporting responsibilities) from those in effect immediately prior
            to the Change in Control;

                  (b) a reduction by the Company in the Executive's annual base
            salary as in effect on the date hereof or as the same may be
            increased from time to time except for across-the-board salary
            reductions similarly affecting all senior executives of the Company
            and all senior executives of any Person in control of the Company;

                  (c) the Company's requiring the Executive to be based anywhere
            other than the Boston Metropolitan Area (or, if different, the
            metropolitan area in which the Company's principal executive offices
            are located immediately prior to the Change in Control) except for
            required travel on the Company business to an extent substantially
            consistent with the Executive's present business travel obligations;

                  (d) the failure by the Company, without the Executive's
            consent, to pay to the Executive any portion of the Executive's
            current compensation, or to pay to the Executive any portion of an
            installment of deferred compensation under any deferred compensation
            program of the Company, within fourteen days of the date such
            compensation is due;

                  (e) the failure by the Company to continue in effect any
            compensation plan in which the Executive participates
<PAGE>   10
                                      -10-


            immediately prior to the Change in Control which is material to the
            Executive's total compensation, or the failure by the Company to
            continue the Executive's participation therein on a basis not
            materially less favorable, both in terms of the amount of benefits
            provided and the level of the Executive's participation relative to
            other participants, as existed at the time of the Change in Control;

                  (f) the failure by the Company to continue to provide the
            Executive with benefits substantially similar to those enjoyed by
            the Executive under any of the Company' s pension, life insurance,
            medical, health and accident, or disability plans in which the
            Executive was participating at the time of the Change in Control,
            the taking of any action by the Company which would directly or
            indirectly materially reduce any of such benefits or deprive the
            Executive of any material fringe benefit enjoyed by the Executive at
            the time of the Change in Control, or the failure by the Company to
            provide the Executive with the number of paid vacation days to which
            the Executive is entitled on the basis of years of service with the
            Company in accordance with the Company's normal vacation policy in
            effect at the time of the Change in Control; or

                  (g) any purported termination of the Executive's employment
            which is not effected pursuant to a Notice of Termination satisfying
            the requirements of Section 5.1.

      "Notice of Termination" shall have the meaning stated in Section 5.1.

      "Person" shall have the meaning given in Section 3(a)(9) of the Exchange
Act, as modified and used in Sections 13(d) and 14(d). thereof; however, a
Person shall not include (i) the Company or any of its subsidiaries, (ii) a
trustee or other fiduciary holding securities under an employee benefit plan of
the Company or any of its subsidiaries, (iii) an underwriter temporarily holding
securities pursuant to a registered offering of such securities in accordance
with an agreement with the Company, or (iv) a corporation owned, directly or
indirectly, by the stockholders of the Company in substantially the same
proportions as their ownership of stock of the Company.

      "Potential Change in Control" shall be deemed to have occurred if the
conditions set forth in any one of the following paragraphs shall have been
satisfied:
<PAGE>   11
                                      -11-


                  (a) the Company enters into an agreement, the consummation of
            which would result in the occurrence of a Change in Control;

                  (b) the Company or any Person publicly announces an intention
            to take or to consider taking actions which, if consummated, would
            constitute a Change in Control;

                  (c) any Person becomes the Beneficial Owner, directly or
            indirectly, of securities of the Company representing fifteen
            percent or more of the combined voting power of the Company's then
            outstanding securities (entitled to vote generally for the election
            of directors); or

                  (d) the Board adopts a resolution to the effect that, for
            purposes of this Agreement, a Potential Change in Control has
            occurred.

      "Severance Payments" shall mean those payments described in Section 3.2
hereof.

      "Total Payments" shall mean those payments described in Section 4 hereof.

      IN WITNESS WHEREOF, the Company and the Executive have executed and
delivered this Agreement on the date first written above.



                                   ASPEN TECHNOLOGY, INC.



                                   By:__________________________________________





                                   _____________________________________________
                                                  Mary A. Palermo

<PAGE>   1

                                                                   Exhibit 10.28

                           CHANGE IN CONTROL AGREEMENT

         AGREEMENT dated as of August 12, 1997 by and between Aspen Technology,
Inc., a Massachusetts corporation (the "Company"), and Joel B. Rosen (the
"Executive").

         WHEREAS, the Company considers it essential to the best interests of
its stockholders to foster the continuous employment of key management
personnel; and

         WHEREAS, the Company has determined that appropriate steps should be
taken to reinforce and encourage the continued attention and dedication of
members of the Company's management, including the Executive, to their assigned
duties with the Company without distraction in the face of potentially
disturbing circumstances arising from the possibility of a Change in Control (as
defined herein);

         NOW THEREFORE, in consideration of the premises and the mutual
covenants herein contained, and for other valuable consideration, the Company
and the Executive hereby agree as follows:

         1. Defined Terms. The definitions of capitalized terms used in this
Agreement are provided in the last section hereof.

         2. Term of Agreement. This Agreement shall commence on the date hereof
and shall continue in effect through June 30, 2002. Thereafter, this Agreement
shall be automatically renewed for successive one year terms unless the Company
sends written notice of termination to the Executive at least 60 days before the
expiration date of this Agreement, which termination will be effective at that
expiration date. If a Change in Control shall have occurred during the term of
this Agreement, however, this Agreement shall continue in effect for a period of
three years beyond the last day of the month in which the Change in Control
occurred. Notwithstanding the foregoing provisions of this Section 2, this
Agreement shall terminate, unless earlier terminated in accordance with this
Agreement, (i) one year after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee, upon recommendation of the
Company's chief executive officer, has voted to terminate this Agreement or (ii)
if earlier, immediately after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee has determined that the
Executive's level of responsibility (other than reporting responsibility) has
substantially changed from the Executive's current level of responsibility,
<PAGE>   2
                                       -2-


in either case only if the notification occurs prior to a Potential Change in
Control that results in a Change in Control.

         3. Payments After Change in Control.

         3.1 If the Executive's employment shall be terminated for any reason
following a Change in Control and during the term of this Agreement, the Company
shall pay the Executive's full salary to the Executive through the Date of
Termination at the rate in effect at the time the Notice of Termination is
given, together with all compensation and benefits payable to the Executive
through the Date of Termination under the terms of any compensation or benefit
plan, program or arrangement maintained by the Company during such period.

         3.2 Subject to Section 3.3, the Company shall pay to the Executive the
payments described in this Section 3.2 (the "Severance Payments") upon the
termination of the Executive's employment following a Change in Control and
during the term of this Agreement, in addition to the payments and benefits
described in Section 3.1, unless such termination is (i) by the Company for
Cause, (ii) by reason of death, (iii) by the Executive without Good Reason, or
(iv) after the Executive shall have attained age 70. In lieu of any further
salary payments to the Executive for periods subsequent to the Date of
Termination and in lieu of any severance benefits otherwise payable to the
Executive under any then existing broad-based employee severance plan, the
Company shall pay to the Executive a lump sum severance payment, in cash, equal
to three times the sum of (x) the higher of the Executive's annual base salary
in effect immediately prior to the occurrence of the event or circumstance upon
which the Notice of Termination is based or in effect immediately prior to the
Change in Control and (y) the higher of the average of the annual bonuses paid
to the Executive for the three years (or the number of years employed, if less)
immediately preceding the occurrence of the event or circumstance upon which the
Notice of Termination is based or the Change in Control. In lieu of any further
life, disability, accident and health insurance benefits otherwise due to the
Executive, the Company shall pay to the Executive a lump sum amount, in cash,
equal to the cost to the Company (as determined by the Company in good faith
with reference to its most recent actual experience) of providing such benefits,
to the extent that the Executive is eligible to receive such benefits
immediately prior to the Notice of Termination, for a period of three years
commencing on the Date of Termination.

         3.3 The payments provided for in Section 3.2 shall be made not later
than the fifth day following the Date of Termination.
<PAGE>   3
                                       -3-


         3.4 The Company also shall pay to the Executive all legal fees and
expenses incurred by the Executive in seeking to obtain or enforce any benefit
or right provided by this Agreement, payable within five business days after
delivery of the Executive's written requests for payment accompanied with such
evidence of fees and expenses incurred as the Company reasonably may require.

         4. Certain Additional Payments by the Company.

         4.1 Notwithstanding any other provisions of this Agreement, in the
event that any payment or benefit received or to be received by the Executive in
connection with a Change in Control or the termination of the Executive's
employment (all such payments and benefits, including the Severance Payments,
the "Total Payments") is determined to be subject (in whole or part) to the
Excise Tax, then the Executive shall be entitled to receive an additional
payment (a "Gross-Up Payment") in an amount such that after payment by the
Executive of all taxes (including any interest or penalties imposed with respect
to such taxes), including without limitation any income taxes and Excise Tax
imposed upon the Gross-Up Payment, the Executive retains an amount equal to the
Total Payments. Notwithstanding the foregoing provisions of this Section 4.1, if
it shall be determined that the Executive is entitled to a Gross-Up Payment, but
that the Total Payments do not exceed 110% of the greatest amount (the "Reduced
Amount") that could be paid to the Executive such that the receipt thereof would
not give rise to any Excise Tax, then no Gross-Up Payment shall be made to the
Executive and the Total Payments shall be reduced to the Reduced Amount.

         4.2 All determinations required to be made under this Section 4,
including whether and when a Gross-Up Payment is required and the amount of such
Gross-Up Payment and the assumptions to be utilized in arriving at such
determination, shall be made by the Company's accountants or such other
certified public accounting firm reasonably acceptable to the Company as may be
designated by the Executive (the "Accounting Firm") which shall provide detailed
supporting calculations both to the Company and the Executive.

         5. Termination Procedures.

         5.1 Notice of Termination. After a Change in Control and during the
term of this Agreement, any purported termination of the Executive's employment
(other than by reason of death) shall be communicated by written Notice of
Termination from one party hereto to the other party hereto in accordance with
Section 8. Further, a Notice of Termination for Cause is required to include a
copy of a resolution duly adopted by the
<PAGE>   4
                                       -4-


affirmative vote of not less than three-quarters of the entire membership of the
Board at a meeting of the Board which was called and held for the purpose of
considering such termination (after reasonable notice to the Executive and an
opportunity for the Executive, together with the Executive's counsel, to be
heard before the Board) finding that, in the good faith opinion of the Board,
the Executive was guilty of conduct set forth in the definition of Cause.

         5.2 Date of Termination. "Date of Termination", with respect to any
purported termination of the Executive's employment after a Change in Control
and during the term of this Agreement, shall mean the date specified in the
Notice of Termination (which, in the case of a termination by the Company
otherwise than for Cause, shall not be less than thirty days and, in the case of
a termination by the Executive, shall not be less than fifteen days nor more
than sixty days, respectively, from the date such Notice of Termination is
given).

         6. No Mitigation. If the Executive's employment by the Company is
terminated during the term of this Agreement, the Executive is not required to
seek other employment or to attempt in any way to reduce any amounts payable to
the Executive by the Company pursuant to Section 3. Further, the amount of any
payment or benefit provided for in Section 3 shall not be reduced by any
compensation earned by the Executive as the result of employment by another
employer, by retirement benefits, by offset against any amount claimed to be
owed by the Executive to the Company, or otherwise.

         7. Executive's Covenants. The Executive agrees that, subject to the
terms and conditions of this Agreement, in the event of a Potential Change in
Control during the term of this Agreement, the Executive will remain in the
employ of the Company until the earliest of (i) a date which is six months from
the date of such Potential Change of Control, (ii) the date of a Change in
Control, (iii) the date of termination by the Executive of the Executive's
employment for Good Reason (determined by treating the Potential Change in
Control as a Change in Control in applying the definition of Good Reason), by
reason of death or Retirement; or (iv) the termination by the Company of the
Executive's employment for any reason.

         8. Successors; Binding Agreement.

         8.1 In addition to any obligations imposed by law upon any successor to
the Company, the Company will require any successor (whether direct or indirect,
by purchase, merger, consolidation or otherwise) to all or substantially all of
the business and/or assets of the
<PAGE>   5
                                       -5-


Company to expressly assume and agree to perform this Agreement in the same
manner and to the same extent that the Company would be required to perform it
if no such succession had taken place. Failure of the Company to obtain such
assumption and agreement prior to the effectiveness of any such succession shall
be a breach of this Agreement and shall entitle the Executive to compensation
from the Company in the same amount and on the same terms as the Executive would
be entitled to hereunder if the Executive were to terminate the Executive's
employment for Good Reason after a Change in Control, except that, for purposes
of implementing the foregoing, the date on which any such succession becomes
effective shall be deemed the Date of Termination.

         8.2 This Agreement shall inure to the benefit of and be enforceable by
the Executive's personal or legal representatives. If the Executive shall die
while any amount would still be payable to the Executive hereunder (other than
amounts which, by their terms, terminate upon the death of the Executive) if the
Executive had continued to live, all such amounts, unless otherwise provided
herein, shall be paid in accordance with the terms of this Agreement to the
Executive's representatives.

         9. Notices. For the purpose of this Agreement, notices and all other
communications provided for in the Agreement shall be in writing and shall be
deemed to have been duly given when delivered or mailed by United States
certified or registered mail, return receipt requested, postage prepaid,
addressed to the respective addresses set forth below, or to such other address
as either party may have furnished to the other in writing in accordance
herewith, except that notice of change of address shall be effective only upon
actual receipt:

                           To the Company:
                           Aspen Technology, Inc.
                           Ten Canal Park
                           Cambridge, MA  02141

                           Attention:  General Counsel

                           To the Executive:
                           Joel B. Rosen
                           840-3 Old Road To Nine Acre Corner
                           Concord, MA  01742

         10. Miscellaneous. No provision of this Agreement may be modified,
waived or discharged unless such waiver, modification or
<PAGE>   6
                                       -6-


discharge is agreed to in writing and signed by the Executive and such officer
as may be specifically designated by the Board. Except as expressly provided
herein, no waiver by either party hereto at any time of any breach by the other
party hereto of, or compliance with, any condition or provision of this
Agreement to be performed by such other party shall be deemed a waiver of
similar or dissimilar provisions or conditions at the same or at any prior or
subsequent time. No agreements or representations, oral or otherwise, express or
implied, with respect to the subject matter hereof have been made by either
party which are not expressly set forth in this Agreement. The validity,
interpretation, construction and performance of this Agreement shall be governed
by the laws of the Commonwealth of Massachusetts, and this Agreement shall be an
instrument under seal. All references to sections of the Exchange Act or the
Code shall be deemed also to refer to any successor provisions to such sections.
Any payments provided for hereunder shall be paid net of any applicable
withholding required under federal, state or local law and any additional
withholding to which the Executive has agreed.

         11. Settlement of Disputes; Arbitration. All claims by the Executive
for benefits under this Agreement shall be directed to and determined by the
Board and shall be in writing. Any denial by the Board of a claim for benefits
under this Agreement shall be delivered to the Executive in writing and shall
set forth the specific reasons for the denial and the specific provisions of
this Agreement relied upon. Any further dispute or controversy arising under or
in connection with this Agreement shall be settled exclusively by arbitration in
Boston, Massachusetts, in accordance with the rules of the American Arbitration
Association then in effect. Judgment may be entered on the arbitrator' s award
in any court having jurisdiction. The Executive shall, however, be entitled to
seek specific performance of the Executive's right to be paid until the Date of
Termination during the pendency of any dispute or controversy arising under or
in connection with this Agreement.

         12. Definitions. For purposes of this Agreement, the following terms
shall have the meanings indicated below:

                           "Beneficial owner" shall have the meaning defined in
         Rule 13d-3 under the Exchange Act.

                           "Board" shall mean the Board of Directors of the
         Company.

                           "Cause" for termination by the Company of the
         Executive's employment, after any Change in Control, shall mean (i) the
         willful and continued failure by the Executive to
<PAGE>   7
                                       -7-


         substantially perform the Executive's duties with the Company (other
         than any such failure resulting from the Executive's incapacity due to
         physical or mental illness or any such actual or anticipated failure
         after the issuance of a Notice of Termination for Good Reason by the
         Executive) after a written demand for substantial performance is
         delivered to the Executive by the Board, which demand specifically
         identifies the manner in which the Board believes that the Executive
         has not substantially performed the Executive's duties, or (ii) the
         willful engaging by the Executive in gross misconduct which is
         demonstrably and materially injurious to the Company or any of its
         subsidiaries, monetarily or otherwise. No act, or failure to act, on
         the Executive's part shall be deemed "willful" unless done, or omitted
         to be done, by the Executive not in good faith and without reasonable
         belief that the Executive's act, or failure to act, was in the best
         interest of the Company.

                  A "Change in Control" shall be deemed to have occurred if the
         conditions set forth in any one of the following paragraphs shall have
         been satisfied:

                           (a) Continuing Directors constitute two-thirds or
                  less of the membership of the Board, whether as the result of
                  a proxy contest or for any other reason or reasons; or

                           (b) Any Person is or becomes the Beneficial owner,
                  directly or indirectly, of securities of the Company
                  representing twenty-five percent or more of the combined
                  voting power of the Company's then outstanding voting
                  securities; or

                           (c) There is a change in control of the Company of a
                  nature that would be required to be reported on Form 8-K or
                  item 6(e) of Schedule 14A of Regulation 14A or any similar
                  item, schedule or form under the Exchange Act, as in effect at
                  the time of the change, whether or not the Company is then
                  subject to such reporting requirement, including without
                  limitation any merger or consolidation of the Company with any
                  other corporation, other than (i) a merger or consolidation
                  which would result in the voting securities of the Company
                  outstanding immediately prior thereto continuing to represent
                  (either by remaining outstanding or by being converted into
                  voting securities of the surviving or parent entity) fifty-one
                  percent or more of the combined voting power of the voting
                  securities (entitled to vote generally for the
<PAGE>   8
                                                  -8-


                  election of directors) of the Company or such surviving or
                  parent entity outstanding immediately after such merger or
                  consolidation and which would result in those persons who are
                  Continuing Directors immediately prior to such merger or
                  consolidation constituting more than two-thirds of the
                  membership of the Board or the board of such surviving or
                  parent entity immediately after, or subsequently at any time
                  as contemplated by or as a result of, such merger or
                  consolidation or (ii) a merger or consolidation effected to
                  implement a recapitalization of the company (or similar
                  transaction) in which no Person acquired twenty-five percent
                  or more of the combined voting power of the Company's then
                  outstanding securities; or

                           (d) the stockholders of the Company approve a plan of
                  complete liquidation of the Company or an agreement for the
                  sale or disposition by the Company of all or substantially all
                  of the Company's assets (or any transaction having a similar
                  effect).

         "Code" shall mean the Internal Revenue Code of 1986, as amended from
time to time.

         "Company" shall mean Aspen Technology, Inc. and any successor to its
business and/or assets which assumes or agrees to perform this Agreement, by
operation of law or otherwise.

         "Compensation Committee" shall mean the Compensation and Nominating
Committee of the Board.

         "Continuing Director" shall mean any director (i) who has continuously
been a member of the Board since not later than the date of a Potential Change
in Control or (ii) who is a successor of a director described in clause (i), if
such successor (and any intervening successor) shall have been recommended or
elected to succeed a Continuing Director by a majority of the then Continuing
Directors.

         "Date of Termination" shall have the meaning stated in Section 5.2
hereof.

         "Exchange Act" shall mean the Securities Exchange Act of 1934, as
amended from time to time.

         "Excise Tax" shall mean the tax imposed by Section 4999 of the
Code.

<PAGE>   9
                                       -9-


         "Executive" shall mean the individual named in the first paragraph of
this Agreement.

         "Good Reason" for termination by the Executive of the Executive's
employment shall mean the occurrence (without the Executive's express written
consent) of any one of the following acts or failures to act by the Company
unless, in the case of any act or failure to act described in paragraph (a),
(e), (f) or (g) below, such act or failure to act is corrected prior to the Date
of Termination specified in the Notice of Termination given in respect thereof
or, in the case of paragraph (c) below, such act is not objected to in writing
by the Executive within four months after notification by the Company to the
Executive of the Company's intention to take the action contemplated by such
paragraph (c):

                           (a) the assignment to the Executive of any duties
                  inconsistent with the Executive's status as a senior executive
                  officer of the Company or a meaningful alteration, adverse to
                  the Executive, in the nature or status of the Executive's
                  responsibilities (other than reporting responsibilities) from
                  those in effect immediately prior to the Change in Control;

                           (b) a reduction by the Company in the Executive's
                  annual base salary as in effect on the date hereof or as the
                  same may be increased from time to time except for
                  across-the-board salary reductions similarly affecting all
                  senior executives of the Company and all senior executives of
                  any Person in control of the Company;

                           (c) the Company's requiring the Executive to be based
                  anywhere other than the Boston Metropolitan Area (or, if
                  different, the metropolitan area in which the Company's
                  principal executive offices are located immediately prior to
                  the Change in Control) except for required travel on the
                  Company business to an extent substantially consistent with
                  the Executive's present business travel obligations;

                           (d) the failure by the Company, without the
                  Executive's consent, to pay to the Executive any portion of
                  the Executive's current compensation, or to pay to the
                  Executive any portion of an installment of deferred
                  compensation under any deferred compensation program of the
                  Company, within fourteen days of the date such compensation is
                  due;

                           (e) the failure by the Company to continue in effect
                  any compensation plan in which the Executive participates
<PAGE>   10
                                      -10-


                  immediately prior to the Change in Control which is material
                  to the Executive's total compensation, or the failure by the
                  Company to continue the Executive's participation therein on a
                  basis not materially less favorable, both in terms of the
                  amount of benefits provided and the level of the Executive's
                  participation relative to other participants, as existed at
                  the time of the Change in Control;

                           (f) the failure by the Company to continue to provide
                  the Executive with benefits substantially similar to those
                  enjoyed by the Executive under any of the Company' s pension,
                  life insurance, medical, health and accident, or disability
                  plans in which the Executive was participating at the time of
                  the Change in Control, the taking of any action by the Company
                  which would directly or indirectly materially reduce any of
                  such benefits or deprive the Executive of any material fringe
                  benefit enjoyed by the Executive at the time of the Change in
                  Control, or the failure by the Company to provide the
                  Executive with the number of paid vacation days to which the
                  Executive is entitled on the basis of years of service with
                  the Company in accordance with the Company's normal vacation
                  policy in effect at the time of the Change in Control; or

                           (g) any purported termination of the Executive's
                  employment which is not effected pursuant to a Notice of
                  Termination satisfying the requirements of Section 5.1.

         "Notice of Termination" shall have the meaning stated in Section 5.1.

         "Person" shall have the meaning given in Section 3(a)(9) of the
Exchange Act, as modified and used in Sections 13(d) and 14(d). thereof;
however, a Person shall not include (i) the Company or any of its subsidiaries,
(ii) a trustee or other fiduciary holding securities under an employee benefit
plan of the Company or any of its subsidiaries, (iii) an underwriter temporarily
holding securities pursuant to a registered offering of such securities in
accordance with an agreement with the Company, or (iv) a corporation owned,
directly or indirectly, by the stockholders of the Company in substantially the
same proportions as their ownership of stock of the Company.

         "Potential Change in Control" shall be deemed to have occurred if the
conditions set forth in any one of the following paragraphs shall have been
satisfied:

<PAGE>   11
                                                  -11-

                           (a) the Company enters into an agreement, the
                  consummation of which would result in the occurrence of a
                  Change in Control;

                           (b) the Company or any Person publicly announces an
                  intention to take or to consider taking actions which, if
                  consummated, would constitute a Change in Control;

                           (c) any Person becomes the Beneficial Owner, directly
                  or indirectly, of securities of the Company representing
                  fifteen percent or more of the combined voting power of the
                  Company's then outstanding securities (entitled to vote
                  generally for the election of directors); or

                           (d) the Board adopts a resolution to the effect that,
                  for purposes of this Agreement, a Potential Change in Control
                  has occurred.

         "Severance Payments" shall mean those payments described in Section 3.2
hereof.

         "Total Payments" shall mean those payments described in Section 4
hereof.

         IN WITNESS WHEREOF, the Company and the Executive have executed and
delivered this Agreement on the date first written above.




                                            ASPEN TECHNOLOGY, INC.




                                            By:
                                                 -------------------------------





                                                 -------------------------------
                                                       Joel B. Rosen




<PAGE>   1
                                                                   EXHIBIT 10.29




                           CHANGE IN CONTROL AGREEMENT

      AGREEMENT dated as of August 12, 1997 by and between Aspen Technology,
Inc., a Massachusetts corporation (the "Company"), and Stephen J. Doyle (the
"Executive").

      WHEREAS, the Company considers it essential to the best interests of its
stockholders to foster the continuous employment of key management personnel;
and

      WHEREAS, the Company has determined that appropriate steps should be taken
to reinforce and encourage the continued attention and dedication of members of
the Company's management, including the Executive, to their assigned duties with
the Company without distraction in the face of potentially disturbing
circumstances arising from the possibility of a Change in Control (as defined
herein);

      NOW THEREFORE, in consideration of the premises and the mutual covenants
herein contained, and for other valuable consideration, the Company and the
Executive hereby agree as follows:

      1. Defined Terms. The definitions of capitalized terms used in this
Agreement are provided in the last section hereof.

      2. Term of Agreement. This Agreement shall commence on the date hereof and
shall continue in effect through June 30, 2002. Thereafter, this Agreement shall
be automatically renewed for successive one year terms unless the Company sends
written notice of termination to the Executive at least 60 days before the
expiration date of this Agreement, which termination will be effective at that
expiration date. If a Change in Control shall have occurred during the term of
this Agreement, however, this Agreement shall continue in effect for a period of
three years beyond the last day of the month in which the Change in Control
occurred. Notwithstanding the foregoing provisions of this Section 2, this
Agreement shall terminate, unless earlier terminated in accordance with this
Agreement, (i) one year after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee, upon recommendation of the
Company's chief executive officer, has voted to terminate this Agreement or (ii)
if earlier, immediately after the Executive is notified in accordance with
Section 9 hereof that the Compensation Committee has determined that the
Executive's level of responsibility (other than reporting responsibility) has
substantially changed from the Executive's current level of responsibility,
<PAGE>   2
                                      -2-


in either case only if the notification occurs prior to a Potential Change in
Control that results in a Change in Control.

      3. Payments After Change in Control.

      3.1 If the Executive's employment shall be terminated for any reason
following a Change in Control and during the term of this Agreement, the Company
shall pay the Executive's full salary to the Executive through the Date of
Termination at the rate in effect at the time the Notice of Termination is
given, together with all compensation and benefits payable to the Executive
through the Date of Termination under the terms of any compensation or benefit
plan, program or arrangement maintained by the Company during such period.

      3.2 Subject to Section 3.3, the Company shall pay to the Executive the
payments described in this Section 3.2 (the "Severance Payments") upon the
termination of the Executive's employment following a Change in Control and
during the term of this Agreement, in addition to the payments and benefits
described in Section 3.1, unless such termination is (i) by the Company for
Cause, (ii) by reason of death, (iii) by the Executive without Good Reason, or
(iv) after the Executive shall have attained age 70. In lieu of any further
salary payments to the Executive for periods subsequent to the Date of
Termination and in lieu of any severance benefits otherwise payable to the
Executive under any then existing broad-based employee severance plan, the
Company shall pay to the Executive a lump sum severance payment, in cash, equal
to three times the sum of (x) the higher of the Executive's annual base salary
in effect immediately prior to the occurrence of the event or circumstance upon
which the Notice of Termination is based or in effect immediately prior to the
Change in Control and (y) the higher of the average of the annual bonuses paid
to the Executive for the three years (or the number of years employed, if less)
immediately preceding the occurrence of the event or circumstance upon which the
Notice of Termination is based or the Change in Control. In lieu of any further
life, disability, accident and health insurance benefits otherwise due to the
Executive, the Company shall pay to the Executive a lump sum amount, in cash,
equal to the cost to the Company (as determined by the Company in good faith
with reference to its most recent actual experience) of providing such benefits,
to the extent that the Executive is eligible to receive such benefits
immediately prior to the Notice of Termination, for a period of three years
commencing on the Date of Termination.

      3.3 The payments provided for in Section 3.2 shall be made not later than
the fifth day following the Date of Termination.
<PAGE>   3
                                      -3-


      3.4 The Company also shall pay to the Executive all legal fees and
expenses incurred by the Executive in seeking to obtain or enforce any benefit
or right provided by this Agreement, payable within five business days after
delivery of the Executive's written requests for payment accompanied with such
evidence of fees and expenses incurred as the Company reasonably may require.

      4. Certain Additional Payments by the Company.

      4.1 Notwithstanding any other provisions of this Agreement, in the event
that any payment or benefit received or to be received by the Executive in
connection with a Change in Control or the termination of the Executive's
employment (all such payments and benefits, including the Severance Payments,
the "Total Payments") is determined to be subject (in whole or part) to the
Excise Tax, then the Executive shall be entitled to receive an additional
payment (a "Gross-Up Payment") in an amount such that after payment by the
Executive of all taxes (including any interest or penalties imposed with respect
to such taxes), including without limitation any income taxes and Excise Tax
imposed upon the Gross-Up Payment, the Executive retains an amount equal to the
Total Payments. Notwithstanding the foregoing provisions of this Section 4.1, if
it shall be determined that the Executive is entitled to a Gross-Up Payment, but
that the Total Payments do not exceed 110% of the greatest amount (the "Reduced
Amount") that could be paid to the Executive such that the receipt thereof would
not give rise to any Excise Tax, then no Gross-Up Payment shall be made to the
Executive and the Total Payments shall be reduced to the Reduced Amount.

      4.2 All determinations required to be made under this Section 4, including
whether and when a Gross-Up Payment is required and the amount of such Gross-Up
Payment and the assumptions to be utilized in arriving at such determination,
shall be made by the Company's accountants or such other certified public
accounting firm reasonably acceptable to the Company as may be designated by the
Executive (the "Accounting Firm") which shall provide detailed supporting
calculations both to the Company and the Executive.

      5. Termination Procedures.

      5.1 Notice of Termination. After a Change in Control and during the term
of this Agreement, any purported termination of the Executive's employment
(other than by reason of death) shall be communicated by written Notice of
Termination from one party hereto to the other party hereto in accordance with
Section 8. Further, a Notice of Termination for Cause is required to include a
copy of a resolution duly adopted by the
<PAGE>   4
                                      -4-


affirmative vote of not less than three-quarters of the entire membership of the
Board at a meeting of the Board which was called and held for the purpose of
considering such termination (after reasonable notice to the Executive and an
opportunity for the Executive, together with the Executive's counsel, to be
heard before the Board) finding that, in the good faith opinion of the Board,
the Executive was guilty of conduct set forth in the definition of Cause.

      5.2 Date of Termination. "Date of Termination", with respect to any
purported termination of the Executive's employment after a Change in Control
and during the term of this Agreement, shall mean the date specified in the
Notice of Termination (which, in the case of a termination by the Company
otherwise than for Cause, shall not be less than thirty days and, in the case of
a termination by the Executive, shall not be less than fifteen days nor more
than sixty days, respectively, from the date such Notice of Termination is
given).

      6. No Mitigation. If the Executive's employment by the Company is
terminated during the term of this Agreement, the Executive is not required to
seek other employment or to attempt in any way to reduce any amounts payable to
the Executive by the Company pursuant to Section 3. Further, the amount of any
payment or benefit provided for in Section 3 shall not be reduced by any
compensation earned by the Executive as the result of employment by another
employer, by retirement benefits, by offset against any amount claimed to be
owed by the Executive to the Company, or otherwise.

      7. Executive's Covenants. The Executive agrees that, subject to the terms
and conditions of this Agreement, in the event of a Potential Change in Control
during the term of this Agreement, the Executive will remain in the employ of
the Company until the earliest of (i) a date which is six months from the date
of such Potential Change of Control, (ii) the date of a Change in Control, (iii)
the date of termination by the Executive of the Executive's employment for Good
Reason (determined by treating the Potential Change in Control as a Change in
Control in applying the definition of Good Reason), by reason of death or
Retirement; or (iv) the termination by the Company of the Executive's employment
for any reason.

      8. Successors; Binding Agreement.

      8.1 In addition to any obligations imposed by law upon any successor to
the Company, the Company will require any successor (whether direct or indirect,
by purchase, merger, consolidation or otherwise) to all or substantially all of
the business and/or assets of the
<PAGE>   5
                                      -5-


Company to expressly assume and agree to perform this Agreement in the same
manner and to the same extent that the Company would be required to perform it
if no such succession had taken place. Failure of the Company to obtain such
assumption and agreement prior to the effectiveness of any such succession shall
be a breach of this Agreement and shall entitle the Executive to compensation
from the Company in the same amount and on the same terms as the Executive would
be entitled to hereunder if the Executive were to terminate the Executive's
employment for Good Reason after a Change in Control, except that, for purposes
of implementing the foregoing, the date on which any such succession becomes
effective shall be deemed the Date of Termination.

      8.2 This Agreement shall inure to the benefit of and be enforceable by the
Executive's personal or legal representatives. If the Executive shall die while
any amount would still be payable to the Executive hereunder (other than amounts
which, by their terms, terminate upon the death of the Executive) if the
Executive had continued to live, all such amounts, unless otherwise provided
herein, shall be paid in accordance with the terms of this Agreement to the
Executive's representatives.

      9. Notices. For the purpose of this Agreement, notices and all other
communications provided for in the Agreement shall be in writing and shall be
deemed to have been duly given when delivered or mailed by United States
certified or registered mail, return receipt requested, postage prepaid,
addressed to the respective addresses set forth below, or to such other address
as either party may have furnished to the other in writing in accordance
herewith, except that notice of change of address shall be effective only upon
actual receipt:

                  To the Company:
                  Aspen Technology, Inc.
                  Ten Canal Park
                  Cambridge, MA  02141

                  Attention:  General Counsel

                  To the Executive:
                  Stephen J. Doyle
                  16 Ledge Hill Road
                  Southborough, MA  01772

      10. Miscellaneous. No provision of this Agreement may be modified, waived
or discharged unless such waiver, modification or
<PAGE>   6
                                      -6-


discharge is agreed to in writing and signed by the Executive and such officer
as may be specifically designated by the Board. Except as expressly provided
herein, no waiver by either party hereto at any time of any breach by the other
party hereto of, or compliance with, any condition or provision of this
Agreement to be performed by such other party shall be deemed a waiver of
similar or dissimilar provisions or conditions at the same or at any prior or
subsequent time. No agreements or representations, oral or otherwise, express or
implied, with respect to the subject matter hereof have been made by either
party which are not expressly set forth in this Agreement. The validity,
interpretation, construction and performance of this Agreement shall be governed
by the laws of the Commonwealth of Massachusetts, and this Agreement shall be an
instrument under seal. All references to sections of the Exchange Act or the
Code shall be deemed also to refer to any successor provisions to such sections.
Any payments provided for hereunder shall be paid net of any applicable
withholding required under federal, state or local law and any additional
withholding to which the Executive has agreed.

      11. Settlement of Disputes; Arbitration. All claims by the Executive for
benefits under this Agreement shall be directed to and determined by the Board
and shall be in writing. Any denial by the Board of a claim for benefits under
this Agreement shall be delivered to the Executive in writing and shall set
forth the specific reasons for the denial and the specific provisions of this
Agreement relied upon. Any further dispute or controversy arising under or in
connection with this Agreement shall be settled exclusively by arbitration in
Boston, Massachusetts, in accordance with the rules of the American Arbitration
Association then in effect. Judgment may be entered on the arbitrator' s award
in any court having jurisdiction. The Executive shall, however, be entitled to
seek specific performance of the Executive's right to be paid until the Date of
Termination during the pendency of any dispute or controversy arising under or
in connection with this Agreement.

      12. Definitions. For purposes of this Agreement, the following terms shall
have the-meanings indicated below:

                  "Beneficial owner" shall have the meaning defined in Rule
      13d-3 under the Exchange Act.

                  "Board" shall mean the Board of Directors of the Company.

                  "Cause" for termination by the Company of the Executive's
      employment, after any Change in Control, shall mean (i) the willful and
      continued failure by the Executive to
<PAGE>   7
                                      -7-


      substantially perform the Executive's duties with the Company (other than
      any such failure resulting from the Executive's incapacity due to physical
      or mental illness or any such actual or anticipated failure after the
      issuance of a Notice of Termination for Good Reason by the Executive)
      after a written demand for substantial performance is delivered to the
      Executive by the Board, which demand specifically identifies the manner in
      which the Board believes that the Executive has not substantially
      performed the Executive's duties, or (ii) the willful engaging by the
      Executive in gross misconduct which is demonstrably and materially
      injurious to the Company or any of its subsidiaries, monetarily or
      otherwise. No act, or failure to act, on the Executive's part shall be
      deemed "willful" unless done, or omitted to be done, by the Executive not
      in good faith and without reasonable belief that the Executive's act, or
      failure to act, was in the best interest of the Company.

            A "Change in Control" shall be deemed to have occurred if the
      conditions set forth in any one of the following paragraphs shall have
      been satisfied:

                  (a) Continuing Directors constitute two-thirds or less of the
            membership of the Board, whether as the result of a proxy contest or
            for any other reason or reasons; or

                  (b) Any Person is or becomes the Beneficial owner, directly or
            indirectly, of securities of the Company representing twenty-five
            percent or more of the combined voting power of the Company's then
            outstanding voting securities; or

                  (c) There is a change in control of the Company of a nature
            that would be required to be reported on Form 8-K or item 6(e) of
            Schedule 14A of Regulation 14A or any similar item, schedule or form
            under the Exchange Act, as in effect at the time of the change,
            whether or not the Company is then subject to such reporting
            requirement, including without limitation any merger or
            consolidation of the Company with any other corporation, other than
            (i) a merger or consolidation which would result in the voting
            securities of the Company outstanding immediately prior thereto
            continuing to represent (either by remaining outstanding or by being
            converted into voting securities of the surviving or parent entity)
            fifty-one percent or more of the combined voting power of the voting
            securities (entitled to vote generally for the
<PAGE>   8
                                      -8-


            election of directors) of the Company or such surviving or parent
            entity outstanding immediately after such merger or consolidation
            and which would result in those persons who are Continuing Directors
            immediately prior to such merger or consolidation constituting more
            than two-thirds of the membership of the Board or the board of such
            surviving or parent entity immediately after, or subsequently at any
            time as contemplated by or as a result of, such merger or
            consolidation or (ii) a merger or consolidation effected to
            implement a recapitalization of the company (or similar transaction)
            in which no Person acquired twenty-five percent or more of the
            combined voting power of the Company's then outstanding securities;
            or

                  (d) the stockholders of the Company approve a plan of complete
            liquidation of the Company or an agreement for the sale or
            disposition by the Company of all or substantially all of the
            Company's assets (or any transaction having a similar effect).

      "Code" shall mean the Internal Revenue Code of 1986, as amended from time
to time.

      "Company" shall mean Aspen Technology, Inc. and any successor to its
business and/or assets which assumes or agrees to perform this Agreement, by
operation of law or otherwise.

      "Compensation Committee" shall mean the Compensation and Nominating
Committee of the Board.

      "Continuing Director" shall mean any director (i) who has continuously
been a member of the Board since not later than the date of a Potential Change
in Control or (ii) who is a successor of a director described in clause (i), if
such successor (and any intervening successor) shall have been recommended or
elected to succeed a Continuing Director by a majority of the then Continuing
Directors.

      "Date of Termination" shall have the meaning stated in Section 5.2 hereof.

      "Exchange Act" shall mean the Securities Exchange Act of 1934, as amended
from time to time.

      "Excise Tax" shall mean the tax imposed by Section 4999 of the Code.
<PAGE>   9
                                      -9-


      "Executive" shall mean the individual named in the first paragraph of this
Agreement.

      "Good Reason" for termination by the Executive of the Executive's
employment shall mean the occurrence (without the Executive's express written
consent) of any one of the following acts or failures to act by the Company
unless, in the case of any act or failure to act described in paragraph (a),
(e), (f) or (g) below, such act or failure to act is corrected prior to the Date
of Termination specified in the Notice of Termination given in respect thereof
or, in the case of paragraph (c) below, such act is not objected to in writing
by the Executive within four months after notification by the Company to the
Executive of the Company's intention to take the action contemplated by such
paragraph (c):

                  (a) the assignment to the Executive of any duties inconsistent
            with the Executive's status as a senior executive officer of the
            Company or a meaningful alteration, adverse to the Executive, in the
            nature or status of the Executive's responsibilities (other than
            reporting responsibilities) from those in effect immediately prior
            to the Change in Control;

                  (b) a reduction by the Company in the Executive's annual base
            salary as in effect on the date hereof or as the same may be
            increased from time to time except for across-the-board salary
            reductions similarly affecting all senior executives of the Company
            and all senior executives of any Person in control of the Company;

                  (c) the Company's requiring the Executive to be based anywhere
            other than the Boston Metropolitan Area (or, if different, the
            metropolitan area in which the Company's principal executive offices
            are located immediately prior to the Change in Control) except for
            required travel on the Company business to an extent substantially
            consistent with the Executive's present business travel obligations;

                  (d) the failure by the Company, without the Executive's
            consent, to pay to the Executive any portion of the Executive's
            current compensation, or to pay to the Executive any portion of an
            installment of deferred compensation under any deferred compensation
            program of the Company, within fourteen days of the date such
            compensation is due;

                  (e) the failure by the Company to continue in effect any
            compensation plan in which the Executive participates
<PAGE>   10
                                      -10-


            immediately prior to the Change in Control which is material to the
            Executive's total compensation, or the failure by the Company to
            continue the Executive's participation therein on a basis not
            materially less favorable, both in terms of the amount of benefits
            provided and the level of the Executive's participation relative to
            other participants, as existed at the time of the Change in Control;

                  (f) the failure by the Company to continue to provide the
            Executive with benefits substantially similar to those enjoyed by
            the Executive under any of the Company' s pension, life insurance,
            medical, health and accident, or disability plans in which the
            Executive was participating at the time of the Change in Control,
            the taking of any action by the Company which would directly or
            indirectly materially reduce any of such benefits or deprive the
            Executive of any material fringe benefit enjoyed by the Executive at
            the time of the Change in Control, or the failure by the Company to
            provide the Executive with the number of paid vacation days to which
            the Executive is entitled on the basis of years of service with the
            Company in accordance with the Company's normal vacation policy in
            effect at the time of the Change in Control; or

                  (g) any purported termination of the Executive's employment
            which is not effected pursuant to a Notice of Termination satisfying
            the requirements of Section 5.1.

      "Notice of Termination" shall have the meaning stated in Section 5.1.

      "Person" shall have the meaning given in Section 3(a)(9) of the Exchange
Act, as modified and used in Sections 13(d) and 14(d). thereof; however, a
Person shall not include (i) the Company or any of its subsidiaries, (ii) a
trustee or other fiduciary holding securities under an employee benefit plan of
the Company or any of its subsidiaries, (iii) an underwriter temporarily holding
securities pursuant to a registered offering of such securities in accordance
with an agreement with the Company, or (iv) a corporation owned, directly or
indirectly, by the stockholders of the Company in substantially the same
proportions as their ownership of stock of the Company.

      "Potential Change in Control" shall be deemed to have occurred if the
conditions set forth in any one of the following paragraphs shall have been
satisfied:
<PAGE>   11
                                      -11-


                  (a) the Company enters into an agreement, the consummation of
            which would result in the occurrence of a Change in Control;

                  (b) the Company or any Person publicly announces an intention
            to take or to consider taking actions which, if consummated, would
            constitute a Change in Control;

                  (c) any Person becomes the Beneficial Owner, directly or
            indirectly, of securities of the Company representing fifteen
            percent or more of the combined voting power of the Company's then
            outstanding securities (entitled to vote generally for the election
            of directors); or

                  (d) the Board adopts a resolution to the effect that, for
            purposes of this Agreement, a Potential Change in Control has
            occurred.

      "Severance Payments" shall mean those payments described in Section 3.2
hereof.

      "Total Payments" shall mean those payments described in Section 4 hereof.

      IN WITNESS WHEREOF, the Company and the Executive have executed and
delivered this Agreement on the date first written above.



                                   ASPEN TECHNOLOGY, INC.



                                   By:__________________________________________




                                   _____________________________________________
                                                 Stephen J. Doyle

<PAGE>   1
                                  Exhibit 22.1
                                  ------------

                             Aspen Technology, Inc.
                            As of September 29, 1997

                                        Subsidiary

Aspen Technology, Inc                   Process Modeling Investment Corporation
                                        Industrial Systems, Inc.
                                        AspenTech Securities Corporation
                                        AspenTech Uk, Ltd.
                                        AspenTech, Inc.
                                        B-Jac International, Inc.
                                        NeuralWare, Inc.
                                        The SAST Corporation Limited

Process Modeling Investment             AspenTech Japan Co. Ltd.
Corporation                             AspenTech Asia, Ltd.
                                        AspenTech Europe S.A./N.V.

AspenTech Europe S.A./N.V.              AspenTech Europe B.V.

AspenTech, Inc.                         Setpoint Canada, Ltd.

<PAGE>   1
                                  EXHIBIT 23.1


                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS


As independent public accountants, we hereby consent to the incorporation of our
reports included in this Form 10-K, into the Company's previously filed
Registration Statements File Nos. 33-88298, 33-88300, 33-97094, 333-11651
and 333-21593.



                                                             ARTHUR ANDERSEN LLP

Boston, Massachusetts
September 26, 1997

<TABLE> <S> <C>

<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED FINANCIAL STATEMENTS AS OF JUNE 30, 1997 INCLUDED IN THE COMPANY'S
FORM 10-K FOR SUCH PERIOD, AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO
SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<CURRENCY> U.S. DOLLARS
       
<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          JUN-30-1997
<PERIOD-START>                             JUL-01-1996
<PERIOD-END>                               JUN-30-1997
<EXCHANGE-RATE>                                      1
<CASH>                                          16,091
<SECURITIES>                                    15,843
<RECEIVABLES>                                   56,624
<ALLOWANCES>                                         0
<INVENTORY>                                          0
<CURRENT-ASSETS>                               115,024
<PP&E>                                          47,338
<DEPRECIATION>                                (19,904)
<TOTAL-ASSETS>                                 192,264
<CURRENT-LIABILITIES>                           44,013
<BONDS>                                              0
                                0
                                          0
<COMMON>                                         2,036
<OTHER-SE>                                     129,405
<TOTAL-LIABILITY-AND-EQUITY>                   192,264
<SALES>                                         97,240
<TOTAL-REVENUES>                               180,299
<CGS>                                            4,538
<TOTAL-COSTS>                                   53,240
<OTHER-EXPENSES>                                31,153
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                 22,754
<INCOME-TAX>                                     9,599
<INCOME-CONTINUING>                             17,792
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    13,155
<EPS-PRIMARY>                                      .63
<EPS-DILUTED>                                      .63
        

</TABLE>


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