Fuzzy logic based decision model for product design

A fuzzy decision-making method for selecting an optimum design from various design alternatives is proposed. The development of a juicer is taken as an example in this study. The evaluation objectives are arrangd in a hierarchial structure with several levels. The relative contribution (weighting function) of each objective to the overall value of the solution and the rating or degree of approximation of a solution with respect to a given objective are quantified with the membership functions of a fuzzy set. A computer program built with a weighted generalized mean method is used to calculate the fuzzy probability level by level from the lowest-level objectives. After the fuzzy expected values of the top-level objectives are calculated, they are then used to make a decision quantitatively on selecting the optimal design alternative. This method can also be used to solve other design problems.