A compromise weight for multi-criteria group decision making with individual preference

In a multi-criteria group decision making process, it is often hard to obtain a solution due to the possible conflict preferences from different participants and the undeterministic weights assigned to each criterion. This problem can be defined as to identify a set of weights for the given criteria to achieve a compromise of the conflict on different preferences. When such a compromise weight does not exist, we need to adjust (to reverse or to withdraw) some or all of the preferences from different participants. This paper describes a minimax principle based procedure of preference adjustments with a finite number of steps to find the compromise weight. At each iteration, we either find the weight or identify some ‘wrong’ preferences. We also define a consistency index for each participant to measure the distance between the individuals' preference and the final group decision. Corresponding theoretical work is referred to in support of the procedure, and numerical examples are provided for illustration. This study is further extended to the case of multiple assessments.