INCORPORATING END-USERS ATTITUDES TOWARDS UNCERTAINTY INTO AN EXPERT-SYSTEM

Uncertainty is a real and unavoidable part of the design process. Unce rtainty in the area of manufacturing cost estimation can have a negati ve impact on the desirability of design alternatives, and some might b e deemed ''too risky'' for further consideration in spite of potential benefits. Expert designers obtain a sense of what level of risk is ac ceptable for different types of applications. Expert systems for desig n thus might include a set of necessary and reasonable assumptions whi ch reflect a particular expert's attitude towards risk and uncertainty . These assumptions may not be applicable for all users. In this paper we present an expert system for design which explicitly addresses the individual user's attitude towards uncertainty. We have developed a s preadsheet user-interface for assessing this attitude through a utilit y function, and for linking those results to a heuristic rule base. Th e heuristic rule base contains only technical expertise used to determ ine a set of feasible alternatives, while the process of evaluating an d ranking these feasible alternatives is driven by the user's individu al preferences and risk-taking profile.