Fuzzy efficiency: Multiplier and enveloping CCR ‎models‎

Comparing the performance of a set of activities or organizations under uncertainty environment has been performed by means of fuzzy data envelopment analysis (fdea) since the traditional dea models require accurate and precise performance data. as regards a method for dealing with uncertainty environment, many researchers have introduced dea models in fuzzy environment. some of these models are solved by transforming fuzzy models into their crisp counterparts. in this paper applying a fuzzy metric and a ranking function, obtained from it, the multiplier fuzzy ccr model converts to its crisp counterpart. solving this model yields the optimal solution of fuzzy multiplier model. moreover, in the following some properties and theorems about mentioned enveloping and multiplier models have been ‎proved