Imprecision in Engineering Design

Manuscript prepared for the
IDEA'97 - Intelligent Design in Engineering Applications Symposium
at the
5th European Congress on Intelligent Techniques and and Soft Computing - EUFIT'97
September 11, 1997, Aachen, Germany.

Erik K. Antonsson
Engineering Design Research Laboratory
Division of Engineering and Applied Science
California Institute of Technology
Pasadena, California 91125


The decisions with the greatest importance and potential cost (if wrong) are made early in the engineering design process. A method for representing and manipulating imprecise and vague information in design is described, particularly focused on the preliminary phase when the (fuzzy) imprecision and uncertainty in the descriptions of the design artifact are high. The preferences of designers and customers are captured with fuzzy sets. Formal methods for including noise, trade-off strategies and design iteration are included. Increasing the information available to a designer will reduce the risk of making design decisions incorrectly. Providing (fuzzy) set-based information to engineers can facilitate concurrency in design.