Release Details

CAMBRIDGE, Mass.--(BUSINESS WIRE)--March 7, 2006-- Aspen Technology, Inc. (NASDAQ: AZPN) today announced the availability of an innovative application that enables customers to significantly increase the value of their investment in simulation technologies. Aspen Simulation Workbook provides integration between AspenTech's process simulation applications - such as Aspen Plus(R) and Aspen HYSYS(R) - and Microsoft Excel, with no programming expertise required. The integration creates new opportunities for companies to use process models for operational decision making and to streamline their conceptual design workflows.

To allow customers to experience the capabilities provided by Aspen Simulation Workbook, AspenTech is currently running a free web-based trial program. Further details about the program can be found at www.aspentech.com/sws.

Aspen Plus and Aspen HYSYS, along with Excel, are the most commonly used tools in process engineering, both for supporting plant operations and in process design. Integrating AspenTech's simulators with Excel opens up a new range of possibilities for users who are not experts in simulation to make use of process models in plant operations and increase the quality and speed of conceptual design work. Aspen Simulation Workbook is built on the Aspen Open Simulation Environment (OSE)(TM) which is the integration environment that allows users to share the same internal and third-party engineering and operations models.

Some of the key capabilities made possible by Aspen Simulation Workbook include:

• solving plant operating problems by creating simple Excel-based user interfaces to rigorous simulation models
• reducing the effort to maintain and validate plant process models by making it easy to input real plant data
• automating data transfer between simulation applications and Excel-based engineering tools, such as costing or equipment design programs.

The value delivered by Aspen Simulation Workbook has already been recognized by a number of leading companies. ABB Engineering Services, which provides simulation, energy, environmental and safety consultancy services to the process industries, has selected the product to improve the execution of simulation projects that require the use of multiple applications, including AspenTech's simulation products and other design tools.

"Aspen Simulation Workbook has enabled us to integrate Aspen Plus and Aspen FIHR(TM) with a third-party design program without the need to develop custom software," said John Martin, Senior Process Consultant, ABB Engineering Services. "The project requires data to be repeatedly transferred between the three applications. Aspen Simulation Workbook allows us to connect them together with a simple, off-the-shelf solution that is easy to use and maintain."

"Our major customers already garner tremendous value from our process simulation applications," said Blair Wheeler, Senior Vice President, AspenTech. "Aspen Simulation Workbook enables those customers to extend that value, and to make it accessible to a broader range of non-expert users. This creates significant new potential to use process models as part of day-to-day operational decision-making, as well as increasing efficiency and productivity during conceptual design."

About ABB

ABB Engineering Services is based at Daresbury, Warrington, UK and is part of the ABB Group, a leader in power and automation technologies that enable utility and industry customers to improve their performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 104,000 people. ABB Engineering Services is a leading provider of simulation, energy, environmental and safety consultancy services to the process industries. For more information, visit www.abb.com/service.

About AspenTech

Aspen Technology, Inc. provides industry-leading software and professional services that help process companies improve efficiency and profitability by enabling them to model, manage and control their operations. AspenTech's integrated aspenONE(TM) solutions are aligned with the key industry business processes, providing manufacturers the capabilities they need to optimize operational performance, make real-time decisions and synchronize the plant and supply chain. Over 1,500 leading companies already rely on AspenTech's software, including Bayer, BASF, BP, Chevron Corporation, DuPont, ExxonMobil, Fluor, GlaxoSmithKline, Sanofi-Aventis, Shell, and Total. For more information, visit www.aspentech.com.

This press release may contain forward-looking statements for purposes of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Actual results may vary significantly from AspenTech's expectations based on a number of risks and uncertainties, including, without limitation: AspenTech's plan to improve operational performance may not be implemented effectively; AspenTech has identified material weaknesses in its internal controls with respect to software license revenue recognition and other matters, that, if not remedied effectively, could result in material misstatements; risks around securities litigation and investigations; AspenTech's lengthy sales cycle makes it difficult to predict quarterly operating results; fluctuations in AspenTech's quarterly operating results; AspenTech's dependence on customers in the cyclical chemicals, petrochemicals and petroleum industries; the possibility of new accounting standards or the interpretation of existing accounting standards affecting our financial results; AspenTech's ability to raise additional capital as required; intense competition; AspenTech's need to develop and market products successfully; reliance on relationships with strategic partners; challenges associated with international operations; and other risk factors described from time to time in AspenTech's periodic reports filed with the Securities and Exchange Commission. AspenTech cannot guarantee any future results, levels of activity, performance, or achievements. AspenTech expressly disclaims any current intention to update forward-looking statements after the date of this press release.

AspenTech, aspenONE, Aspen Simulation Workbook, Aspen Plus, Aspen HYSYS, Aspen FIHR, Aspen Open Simulation Environment and the aspen leaf logo are trademarks of Aspen Technology, Inc., Cambridge, Mass. Microsoft Excel is a trademark of Microsoft Corporation.

CONTACT:
Aspen Technology, Inc.
Media:
Marie Telepneff, 617-949-1324
marie.telepneff@aspentech.com

Investors:
AspenTech Investor Relations
617-949-1624 or 888-996-7080