An Interval-Valued Multi-attribute Decision Making Based on Combined QUALIFLEX-EAST Methodology.

In the traditional QUALIFLEX method to choose the best ranking order among m alternatives, all m ! permutations of the ranking order of alternatives are considered; however, that is not required always. Besides, the number of permutations increases drastically with an increase in the number of alternatives. To avoid such significant computational intricacy, in this paper we tried to generate only the possible preference orders of alternatives from the decision matrix by implementing the EAST method premised on the graph-theoretic approach. To facilitate this, the proposed decision-making framework considers the transformation of the decision matrix into a pair-wise comparison matrix where the uncertainty is modeled by interval-valued fuzzy sets. The consistency analysis is performed by modeling the interaction between the lower and upper parts of the preference matrix. Further, to evaluate the aggregated value in order to obtain the optimal ranking, we use discrete Choquet integral which can capture some degree of inter-dependence among the attribute set. Finally, the concordance/discordance index analysis is done to choose the best alternative.