Adjustment from Inconsistent Comparisons in AHP to Perfect Consistency

Abstract

In this study, for inconsistent pairwise comparisons in Analytic Hierarchy Process (AHP), a method for improving consistency is proposed. The pairwise comparisons constructed by the decision maker, usually include inconsistent comparisons. In the traditional AHP, the consistency of comparisons is judged by the value of the consistency index (CI). Another consistency judgment is based on the directed graph of comparisons. The purpose of this study is to adjust an inconsistent comparison matrix to a perfect consistency matrix. The proposed method is based on adjusting all the elements of the comparison matrix. The idea of the proposed method is developed based on a previous study of estimating unknown or missing comparisons. By applying the proposed method to an inconsistent example, the process of improvement is illustrated.