Expert systems and computer aided design: a productive merger

An application of expert system concepts is presented for computer-aided design (CAD) environments to show how artificial intelligence can act as a design assistant. This concept is demonstrated by a recent, successful software development effort to implement a digital-circuit CAD tool enhanced by such an expert system for educational use. The discussion centers on the use of graphics, simulation, and expert systems to construct an effective CAD workstation running on personal computer systems. The authors note the use of graphics technology to provide schematic capture which, when coupled with a database system, provides the necessary environment for a rule-based expert system. The CAD tool demonstrates the use of design heuristics, metaknowledge, and integrated-circuit data to construct a forward-chained reasoning mechanism for detecting design errors. The concept is extendable to other graphics-oriented CAD tools. Operating experience with the tool is described and summary performance measures, which serve as possible predictors of other candidate systems performance, are presented. Issues influencing the merger of knowledge-based models and CAD are also briefly discussed