Institut Français du Pétrole and AspenTech to Offer Powerful Solution for the Optimization of Oil and Gas Production Systems

Upstream industry to benefit from the integration of TACITE Hydrodynamic module in the Aspen Engineering Suite™ HYSYS® process modeling environment

CAMBRIDGE, MA—July 28, 2003—Aspen Technology, Inc. (Nasdaq: AZPN) and Institut Français du Pétrole (IFP) today announced an agreement to integrate the TACITE Hydrodynamic module (TACITE-HDM) into HYSYS. The combination of HYSYS, the Aspen Engineering Suite (AES)™ process simulator used for designing and operating oil and gas facilities, and TACITE-HDM, a leading multi-phase flow mechanistic model developed by IFP for designing oil and gas pipelines, will create a powerful new solution for the upstream industry. The combined offering will enable engineers to de-bottleneck and optimize the performance of complete production systems, from the flowlines to the facilities, using an accurate model of their assets.

“IFP is pleased to co-operate with AspenTech on this project,” said Christian Pauchon, Director of the Drilling Production Technology Business Units at IFP. “TACITE-HDM is an accurate two-phase hydrodynamic model that has been validated using real world data from the oil and gas industry. The integration of TACITE-HDM into HYSYS will provide users with an effective new tool to investigate the behavior of existing multi-phase pipelines or to study alternative design methodologies for new systems.”

The TACITE-HDM module was developed by IFP to help oil and gas companies gain a better understanding of the complex multi-phase flows found in pipeline systems. It provides a tool for flow assurance studies from traditional offshore to deep offshore environments, and incorporates local steady-state prediction methods for pressure gradients, liquid hold-up, phase velocities and flow regimes.

“The integration of IFP’s proven hydraulic technology into the AES HYSYS process simulation environment will enable our upstream customers to improve the performance of their production assets,” commented Manolis Kotzabasakis, Sr. Vice President of AspenTech’s Engineering Business. “Accurate hydrodynamic calculations are crucial to pipeline designs and ratings, ensuring optimal operations and improved safety.”

HYSYS is a process modeling tool used in the Oil and Gas and refining industries to identify optimal designs and the most profitable operating scenarios for both new and existing assets. HYSYS enables improved Process Asset Lifecycle Management by helping companies to leverage model-based decision-making across their business in conceptual design, process engineering, operational improvement, performance monitoring and on-line optimization.

Steady-state modeling capabilities using TACITE-HDM will be made available first in the HYSYS TACITE Option planned for release in the third quarter of 2003, while dynamic capabilities will be incorporated in AES at a later date.

About IFP
The Institut Français du Pétrole (IFP) is an independent research and industrial development, education and training, and information center active in the fields of oil, natural gas, and the automobile. Its activities cover all aspects of the oil and gas industry: exploration, production, refining, petrochemicals, engines, and the use of petroleum products. Its direct subsidiaries and its holdings in oil service and supply companies place IFP at the head of a group on an international scale - with activities covering the whole oil service and supply sector, from consulting to engineering and the supplying of products, processes, equipment, and services - that is an important outlet for the industrial development of its technological innovations. For more information, visit www.ifp.fr.

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 Total. 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.

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