An intelligent basis for design

A description is presented of the first steps towards an intelligent CAD system based on a mixed-initiative approach. The expert system is an object-oriented model-based reasoning engine using constraint propagation and dependency backtracking. The architecture is built around the expert system, a CAD engine, and a user interface/controller module mediating the mixed-initiative relationship between designer and system. Initial experience has shown the need to model both experts and objects in the knowledge base and both the need and difficulty of representing design and constraint spaces to the designer. The preliminary results of a study of how people use a CAD system to better understand the design process itself suggest directions for the development of intelligent CAD