O. Nasr Eldin, A. Hussein, S. Kumar, and A. Ashry, Suez Oil Company (SUCO) Abstract Recent advances in computer technology and the proliferation of computers in the workplace have had a big impact on technical decision making and on the day to day work of engineers. In petroleum engineering, we are faced with a variety of complex software, with different functionalities, prices and features. It is quite a challenge to review the options available and to select one which will be the optimum for a significant length of time and provide the company with best tools at the lowest price. This paper presents the philosophy and the methodology involved in the evaluation of software. The compulsions on the part of the suppliers as well as the demands of the customers are discussed. Practical criteria for evaluating software for petroleum engineering applications, evolved through the last decade of experience in several operating companies and with discussions with international suppliers and experts, are presented. The process of evaluation and the criteria and process of selection are described through two real examples, one for reservoir simulation software and the other for well test analysis software, undertaken recently at our company. Detailed tables and check-lists are presented for these two cases which enabled the engineers as well as the management to quickly review the available packages and to decide which one would best meet their needs. A desirable outcome of the process was the fact that we were able to provide the suppliers with a lot of sensible suggestions to improve their products for our benefit. This paper seeks to provide an understanding of the software process lifecycle, from design to sales to usage, in order to allow engineers the necessary insight for evaluating their own given software. The software industry is in such turmoil that these skills are now necessary on a frequent basis for continuous quality improvements which require that engineers find the best solutions to their problems at lowest cost. Introduction Computer software has proliferated because it fills a technical and business need - quick, precise computations, links to other technical processes, efficiency in repeated tasks, fast communication, etc. Computer software is behind all of these roles and is well on the way to acquire additional roles, such as training preservation of human expertise (expert system), intelligent search agents to scan information networks for user-specified information, etc. Form a user perspective, the key attributes of any software application are features and costs. Vendors have made tremendous progress on the former, but are only beginning to address the latter issue. Other issues from the user perspective include support, documentation, timely upgrades, etc. Management views software as a necessary tool for technical work and for designing presentations, but are often frustrated at the high costs, time-consuming computer, maintenance, incompatibility across platforms, rapid changes, intensive training requirements, etc. These problems are real and vendors looking for a competitive advantage must seek solutions as quickly as they can. Vendors seek new customers, increased market share and, above all, profitability. Once a sale is made, vendors rely on annual maintenance fees for expenditures on development and support. The incremental costs for a copy of the package are significant, therefore profitability is crucially dependent on finding new customers. The onus is on the vendors to meet the challenge and balance the customer's needs against their profitability. P. 337^