A FUZZY APPROACH FOR MULTIRESPONSE OPTIMIZATION - AN OFF-LINE QUALITY ENGINEERING PROBLEM

Multiresponse optimization techniques are used to identify settings of process parameters that make the product's performance close to target values in the presence of multiple quality characteristics. In this study, a fuzzy multiresponse optimization procedure is proposed to search an appropriate combination of process parameter settings based on multiple quality characteristics or responses. Fuzzy regression models are first used to model the relations between process parameters and responses. The possibility distributions of the prediction responses are then obtained. The problem is reduced to a multiobjective optimization problem with fuzzy objectives. A strategy of optimizing the most possible response values and minimizing the deviations from the most possible values is proposed. We consider not only the most possible value, but also the imprecision of the prediction responses. Through a die casting example, we show how to use our approach to reach an appropriate machine setting which simultaneously optimize both casting quality and die life.