AspenTech Enhances Solution for Oil & Gas and Refining Markets with Latest Version of HYSYS.

Business Editors/High-Tech Writers

CAMBRIDGE, Mass.--(BUSINESS WIRE)--March 24, 2003

Integrated simulation environment features advances in

steady-state and dynamic capabilities critical for optimal design of

upstream and refining processes

Aspen Technology, Inc. (Nasdaq: AZPN) today announced an enhanced solution for the Upstream Oil & Gas and Refining markets with the release of the latest version of HYSYS(R). Part of the Aspen Engineering Suite (AES(TM)), HYSYS is a fully integrated steady-state and dynamic simulation environment that supports collaborative engineering and promotes engineering-to-business knowledge transfer. HYSYS 3.1 features a range of improvements that will enable companies to optimize the design of upstream and refining processes, and achieve more reliable and stable plant operations.

A tougher market environment and increased competition have forced process manufacturers to improve engineering productivity and enhance decision-making across the enterprise. Environmental restrictions also make it increasingly important for these companies to gain a more comprehensive understanding of their processes. In response to these challenges HYSYS 3.1 incorporates a number of significant new features, including an innovative separation model that allows accurate simulation and understanding of the liquid and gas separations that occur in Oil & Gas plants. The ability to reliably predict phase separation is critical to the safe operation and performance of the capital-intensive rotating equipment employed in many Upstream Oil & Gas processes.

"The Upstream Oil & Gas industry is currently undertaking heavy investments at a very fast rate," said Manolis Kotzabasakis, Sr. Vice President of Engineering at AspenTech. "With our AES Process Asset Lifecycle Management solution, and specifically with HYSYS 3.1, we enable companies to quickly and accurately identify alternatives and implement economically optimum decisions, providing adopters with a strong competitive advantage."

Gas properties available in HYSYS simulations have been extended to include virtually all the key performance indicators used by the Oil & Gas industry to make better operation and engineering decisions. HYSYS 3.1 has been further integrated with the AES Icarus(TM) Economic Evaluation and the AES HTFS(TM) Equipment Design & Rating products to help companies make optimal design and investment decisions. The dynamic capabilities of HYSYS have also been extended to increase ease-of-use and to allow process operability studies to be made seamlessly as part of any engineering or operations improvement project.

The Aspen Engineering Suite is an essential element of AspenTech's solutions for Enterprise Operations Management in the process industries. These integrated, enterprise-wide solutions combine engineering and manufacturing/supply chain technologies to help companies optimize the way they engineer and run their manufacturing and supply chain operations.

About AspenTech

Aspen Technology, Inc. provides industry-leading software and implementation services that enable process companies to increase efficiency and profitability. AspenTech's engineering product line is used to design and improve plants and processes, maximizing returns throughout an asset's operating life. Its manufacturing/supply chain product line allows companies to increase margins in their plants and supply chains, by managing customer demand, optimizing production, and streamlining the delivery of finished products. These two offerings are combined to create solutions for Enterprise Operations Management (EOM), integrated enterprise-wide systems that provide process manufacturers with the capability to dramatically improve their operating performance. Over 1,500 leading companies already rely on AspenTech's software, including Aventis, Bayer, BASF, BP, ChevronTexaco, Dow Chemical, DuPont, ExxonMobil, Fluor, Foster Wheeler, GlaxoSmithKline, Shell, and TotalFinaElf. For more information, visit www.aspentech.com.

Certain paragraphs of this press release contain forward-looking statements for purposes of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. For this purpose, any statement using the term "will," "should," "could," "anticipates," "believes" or a comparable term is a forward-looking statement. Actual results may vary significantly from AspenTech's expectations based on a number of risks and uncertainties, including: AspenTech's lengthy sales cycle which makes it difficult to predict quarterly operating results; fluctuations in AspenTech's quarterly operating results; AspenTech's dependence on customers in cyclical industries; adverse global economic conditions; AspenTech's ability to raise additional capital as required; the FTC's investigation of the Hyprotech acquisition; the outcome of AspenTech's restructuring plans; intense competition; AspenTech's need to develop and market products successfully; and other risk factors described from time to time in AspenTech's periodic reports and registration statements filed with the Securities and Exchange Commission. AspenTech cannot guarantee any future results, levels of activity, performance, or achievements. Moreover, neither AspenTech nor anyone else assumes responsibility for the accuracy and completeness of any forward-looking statements. AspenTech undertakes no obligation to update any of the forward-looking statements after the date of this press release.

AspenTech, Aspen Engineering Suite, HYSYS, Icarus, HTFS and the aspen leaf logo are trademarks of Aspen Technology, Inc., Cambridge, Mass.