Investigation of methods for improving consistency of a pairwise comparison matrix

Abstract

Estimation of quality of expert judgements and their suitability for reliable evaluation of decision alternatives is one of key issues for successful decision-making. The notions of strong and weak consistency are used to estimate the contradiction level of expert pairwise comparison matrix (PCM). Several methods are used to find the most inconsistent elements of a PCM. They may lead to different results, and there is a problem to find an element that has to be changed to increase the consistency level of a PCM. To solve this problem, a novel methodology for analysis of efficiency of methods for finding the most inconsistent elements of a PCM is proposed. An improved M_Outflow method for finding the most inconsistent element and a cycle in a PCM is established. Using computer modelling, it is shown that the proposed M_Outflow method is more efficient under accepted conditions in comparison with other considered methods.

Keywords:

• Decision support systems
• pairwise comparisons
• the most inconsistent judgements
• an efficient improvement of consistency
• simulation

Acknowledgement

The author would like to thank two anonymous reviewers for their constructive comments and suggestions, which have been very helpful in improving the paper.