Analyzing Saaty’s consistency test in pairwise comparison method: a perspective based on linguistic and numerical scale

The consistency test is a vital basis of the pairwise comparison method, which is performed to ensure that the decision maker is being logical in his/her pairwise comparisons. In the analytic hierarchy process, the pairwise comparison method with a fixed numerical scale has been employed. In this study, we provide a systematic review analysis regarding the inconsistency causes in the pairwise comparison method with a fixed numerical scale, and propose the paradoxes on Saaty’s consistency test in this pairwise comparison method. Meanwhile, based on the use of the consistency-driven linguistic methodology, we propose a novel approach from a perspective of the linguistic and numerical scale to deal with the inconsistency in the pairwise comparison method.