A combination of ranking veto concept and distance measures to minimize conflicts in a group decision problem

The main goal of a consensus process is to reach an agreement or at least to minimize conflicts and regrets. Ideas and preferences of an entire group of people are listed and discussed so as to arrive at a final decision acceptable to all participants. The use of a traditional additive model to aggregate individual preferences may produce alternatives that one or more decision makers (DMs) consider are undesirable and which were caused by the compensatory effect of the model. Consequently, a final group ranking of alternatives may not represent the DMs´ main goals and may well not minimize conflicts and disagreements. With a view to mitigating this kind of problem, a group decision method based on Multi-Attribute Utility Theory (MAUT), utility thresholds and distance measure information is proposed. The major contributions of this study are to define a ranking veto concept for an additive model and to use vector representation in order to evaluate the similarities between alternatives. To illustrate the applicability of the model, a water utility problem was tackled to show this numerically.