Analysis of Consistency Indices of Pairwise Comparison Methods

Abstract

The pairwise comparison method is an important tool in the mutual, easy and effective evaluation of factors in the decision-making process. The consistency index (CI) and consistency ratio values determine whether the pairwise comparisons made by the decision makers are performed according to the transitivity and reciprocal properties. Consistency measurement methods in the literature use different computational methods to evaluate the validity of pairwise comparisons. 14 different consistency methods selected from the literature define different consistency index and threshold values to accept the validity of pairwise comparisons. The aim of this study is to observe the behavior and relationships of the consistency indices of 14 different consistency methods in the same and different pairwise comparison matrix (PCM) dimensions. The consistency indices of the methods are compared in all dimensions, and also the random indices of the methods in different dimensions are calculated. According to Saaty's consistency ratio (CR) threshold value (CR≤0.1), threshold values are defined for the consistency indexes of 14 different methods in 8 different dimensions. Thus, decision makers are helped to more easily determine the consistency of pairwise comparisons in different methods and in different dimensions.