A Ranking Procedure for Fuzzy Decision-making in Product Design

The decision-making process is a key issue for most manufacturing and services organizations, and forms an essential part of the product design process. Indeed, designers are always confronted with the dilemma of choosing between different alternatives with different parameters, often expressed in fairly vague terms. For this reason, many tools have been proposed offering more and better ways to improve company decision-making in this area. The ranking of fuzzy numbers is one of the most important of these tools, as fuzzy logic has a powerful capacity to manage the vague parameters usually associated with the expression of product requirements by the human personality. Improving the accuracy of such tools is a way to improve product design. In this vein, an extension of previous algorithms is proposed for the ranking procedure in fuzzy decision-making process. This extension is based on normal trapezoidal fuzzy numbers (and supports rectangular and triangular normal fuzzy numbers as well), instead of traditional triangular fuzzy numbers. The ranking procedure is based on the fuzzy preference relation. A product design example is provided.