Abstract: Based on the analysis of gray target decision making under uncertainty, an interval gray target classification and decision-making model is put forward. In this model,the gray target decision-making is extended to uncertain circumstance in which the interval numbers serve as the decision-making information, and a method for measuring the target-center distances of the interval numbers is proposed. According to the target-center distance, a method for determining the critical values of target-center classification in the gray target classification and decision-making is presented. Besides,a determined model involving the target weights and the critical values of the classification is constructed, aiming at the minimum value of the accumulate deviation between the target-center distances in the case and the critical values.At last, classification and ranking of the new objects are conducted according to the calculated weights and the critical values of the classification. Case analysis shows the proposed model is effective and feasible. As a result, this model can be applied to multi-attribute classification decision-making problems with abundant objects and uncertain number of classification.

Key words: gray target, interval numbers, classification, sample-set, multi-attribute decision making