Kinesys (Knowledge Integration for the Engineering of Systems) is a research and development project initiated at Tractebel Energy Engineering (TEE). Its goal is to provide a knowledge base to the design engineers that capitalizes their know-how in power plant design. Practically, we expect that the systematic elimination of redundancy in design activities will lead to an important reduction of delays in the context of calls for tender issued by potential clients. We also expect an improvement of the quality of the offers thanks to the validation of the designs; and a preservation of the know-how of the company. The Kinesys project was developed by applying a knowledge-level methodology with a strong emphasis on the participation of users in the design of the knowledge system.