Value improvement system for products based on fuzzy approach

In this paper, the value improvement system for products is proposed on the basis of the problem-solving process of value engineering and fuzzy approach. In the proposed method, the nominal group techniques is applied to define the functions of products. A functional block diagram is built up by applying the modified fuzzy structural modeling. The importance degree of function is computed by the ratio method. The value indexes for the parts are computed from the viewpoints of the importance degrees of function and the cost of products. The value control graphic structure for the parts, which shows the balance between cost and function of products, is drawn out to perform the value improvement on the basis of the computational result of the value indexes. Further, in order to promote the value improvement of products totally, an integrated value evaluation of products is computed by making use of the fuzzy integral, which is able to deal with uncertainty inherent in decision makers on the basis of the functional block diagram built up at the previous step. In order to inspect the effectiveness of the proposed method, a practical problem is illustrated as an empirical study: “Value improvement for parts and sub-assembly of the business bag”. The system we propose provides decision-makers with a mechanism to incorporate subjective understanding or insight to evaluation process.