Supplier selection using fuzzy quality data and their applications to touch screen

The purchasing function directly affects the competitive ability of a firm. Since the determination of suitable suppliers from a set of suppliers has become a key strategic consideration, managers need to periodically evaluate suppliers on the basis of their products quality to select suppliers whose quality characteristics of products meet the standards. The quantification of the process capability is effective to understand the quality of the units shipped from a supplier. While fuzzy data commonly exist in our real world, the quality-based supplier selection with fuzzy quality data is proposed in this paper. We apply the resolution identity result, a well-known method used in fuzzy sets theory, in terms of solving the nonlinear programming problems with bounded variables to construct the membership function of a fuzzy capability-index estimate for each supplier. The preferred suppliers are selected by using a ranking method of fuzzy preference relations of suppliers. Finally, a case study of touch screens is provided to describe the applicability that incorporates the fuzzy data into the problem of quality-based supplier selection and evaluation.