Three-dimensional dynamic combined evaluation method and its application to vender evaluation based on gray system theory

A basic part of the logistic management of companies is the purchasing function, and the appropriate evaluation and selection of vendors among them is one of the prime responsibilities of this function. Many conceptual and analytical models have been developed to solve the vendor selection problems. In this paper, the gray system theory and methods are applied to establish the vendor evaluation model, which has the following characters. Firstly, an ideal vendor is built to calculate the relational degree between the appraisal vendor and ideal vendor; Secondly, the weights of attributes are defined by the entropy method; thirdly, the effects of the developing condition on the evaluation result during different period are considered. At last, the validity of the method is explained by an example.