Indifferent Points in The Multicriteria Decision Making Problems (A Case Study of Suppliers’ Evaluation in Zanjan Province Gas Company)

Evaluating and selecting the right contractors can increase the chances of success of a project and the organization. Considering the intense competition faced by organizations today, proper cost management to enhance profitability and customer satisfaction has attracted a lot of attention. The evaluation of contractors is usually a process thatis based on various criteria.By the end of it, theappropriate options are selected. Given the diversity in the criteria and among thedecision-making subjects, no singleway has been offered to suggest substitution between criteria.The desirability indifference on the curve ofconsumption of various goods (selection ofdecision-making options) are the same. This paper seeks to identify parallel matrices with the initial decision-making matrix of contractors that have the same results and desirability for decision-makers (indifference points). At first, the initial rating using the AHP and TOPSIS methods andthe particle swarm optimization (PSO) and genetic algorithm (GA)techniques, along withMATLAB software,was used to identify theparallel matrices. According to the obtained results, sixparallel matrixes with the initial decision-making matrix that had been prepared by experts fromthe company were produced.Out of them, the matrix related to The point of indifference is the fifth output5 AHP-PSO, based on the company experts' opinions was selected as the final version.