We are beginning to see expert systems designed by the experts themselves rather than by experts relying on a knowledge engineer to make the translation. This book presents a computer-based methodology that enhances the aid given to an engineering designer, focusing on component assembly rather than on component manufacture. The author, with the Department of Engineering Design and Manufacture, University of Hull, UK, describes a knowledge-based expert system that provides designers with estimated costs for important phases of automatic assembly and suggests design improvements that could reduce these costs. The system described can be used in a conversational mode with the user supplying all the data on request, or it can be linked to an engineering drawing of a component produced at a CAD workstation.
The structure of the book is as follows:
(1) A brief introduction to the problem of design for economic manufacture. (7 pp.)
(2) A review of design for automation in assembly and of previous design aids. (18 pp.)
(3) Design considerations for a consultation system. (7 pp.)
(4) Computer-based methods for design advice. The author reviews knowledge-based expert systems and briefly describes Prolog. (14 pp.)
(5) A computer-based solution for automation in assembly. The author describes a consultation system that has been used to advise the designer of difficulties that the design presents for automatic handling during manufacture and to suggest remedies. In addition, four main solution stages are described: (1) general feeding of components, (2) orientation of components, (3) presentation of components, and (4) handling system cost. Typical rules for each of these stages are provided. (25 pp.)
(6) Automation advice in CAD. The author describes how a Prolog program can be used to determine properties such as symmetry, internal and external arcs, headed components, and grooves from CAD drawings. (32 pp.)
(7) System performance. The author compares the predictions of the consultation system with those of experts in the field. An evaluation of the prediction of equipment cost and the quality of the design advice is given. (8 pp.)
(8) Prospects and future directions. (8 pp.)
Most design engineers will have trouble with the very abbreviated and somewhat esoteric explanation of Prolog provided. Fortunately, most of the time the rules are presented in their English language form rather than the Prolog clausal form. When Prolog programs are provided, one can pretty much “psych out” what the programs are doing without understanding how they work. This book provides the design engineer with an excellent introduction to the emerging field of knowledge-based design for manufacture. Good references and a good review of the field add to the usefulness of the book. The price seems somewhat high for a 149-page paperback; it is too bad the author did not add an appendix giving further examples of the rules used to evaluate the design and evaluate handling costs.
