Concurrent engineering in an expert system

Concurrent engineering calls for site-specific, simultaneous evaluation of manufacturing cost and other performance measures early in the design process. Rule-based systems incorporate heuristics for design evaluation that might be reasonable and valid for designers in stereotypical situations but inaccurate for others. A method for the prescriptive integration of the actual preferences of individual design engineers into the rule base is presented. The heuristics are analyzed to separate rules that reflect objective technical expertise from those that include assumptions as to preferences of the expert system users. The preference rules are eliminated and dealt with in a more direct manner with multiattribute utility analysis. System performance is enhanced by increasing sensitivity to user´s preferences without disturbing the original expert´s objective knowledge. This approach leads to improved selections for a wider cross section of end users, without compromising system performance. The method is applied to the problem of material selection for automobile bumper fascia, beam, and energy absorber components