Grey fuzzy decision-making method of complex multi-index scheme based on vague set

In solving the decision-making problems of complex multi-index evaluating scheme, the traditional way is to adopt fuzzy unified evaluating method. But the traditional fuzzy evaluating method has a lot of shortcomings, e.g. being unable to fully reflect the intended purpose of fuzzy evaluation, because it is difficult for experts to score an evaluating index definitely; sometimes hardly providing a definite dependence-degree for index evaluation; and sometimes causing a considerable amount of information to be "flooded" in the decision-making process when the decision-making system is rather complicated and there are too many factors to be taken into account, thus each getting only a little factor in the distribution, and even leading to failure of the model. Besides, compared with the factor-dependence-degree-based fuzzy evaluating matrix which takes into consideration only the separate influences of every single influencing factor, the complex scheme is a unified whole, in which all influencing factors cooperatively impose their influence on system attributes, i.e. a typical gray information which should be made full use of in the decision-making process. In view of the shortcomings of traditional fuzzy unified evaluating method, i.e. rough evaluation of indexes and negligence of holistic information in the evaluating process, this thesis proposes a vague set-based index-evaluating method. The multi-attribute fuzzy decision, by introducing gray system theory into the scheme, forms a fuzzy decision-making model based on gray relational analysis. The effectiveness of this method is proved with an example