In the process to design a product, the values of the product will be designed must be considered in respect to the multi-dimensional properties consisted of subjective and objective attributes. As same reason, methods to evaluate the design alternatives in the process must evaluate the overall attributes and relationships among its, also. In this paper, the defectivenesses of evaluation methods in the process of product design are summarized. One of the severe defectivenesses of the methods is the insufficient rationality of calculation procedure. Then, we introduce the developed quantitative evaluation method to accomodate this defectiveness and to be considered a evaluator's feeling or ambiguity when evaluating design alternatives by means of fuzzy theory, and suggest it's application steps on the process of product design to be used easily.