A synergism has begun to surface from the artificial intelligence (AI) and engineering communities: an effort to apply AI techniques to engineering problem-solving activities, and to study problems arisen from various engineering fields as a way to develop AI theories and methodologies. The paper first discusses the needs of such a synergical approach and identifies in a broad perspective some AI techniques currently being applied to engineering. It then describes a system, called KREATOR, which applies qualitative reasoning, a subfield of AI, to computer-aided design (CAD). KREATOR is a knowledge capturing scheme that allows the designers to record their qualitative knowledge of how mechanical devices behave. KREATOR then automatically generates qualitative simulations