Joint improvement of rationality and representativeness in Group Decision Making with the Analytic Hierarchy Process

Two of the most relevant issues in multifactor decision-making are rationality and representativeness. Rationality refers to the consistency of individuals when incorporating their preferences into the formal model (individual coherence) whilst representativeness refers to the compatibility or the individuals’ acceptance of the collective position (group coherence). This paper presents for the first time in the literature a unified (methodologically) and closed (mathematically) framework for the joint improvement of rationality and representativeness in a local AHP-Group Decision Making context in which the collective position is given by a group pairwise comparison matrix. Based on maximising efficiency, the proposal works with slight modifications in relative terms, uncommon in this field, of the judgements of the collective matrix without modifying the initial individual positions. Optimisation results for the judgement that most rapidly increases the efficiency and the value that achieve the maximum improvement are provided. Significant improvements are attained and valuable information for learning and negotiation is gathered. The flexibility of this unified and closed framework allows its adaptation to different interests and situations. Simulation studies and illustrative examples demonstrate the robustness, effectiveness and potential of the framework.