Ideal and anti-ideal decision making units: A fuzzy DEA approach

In this paper, by introducing two virtual decision-making units (dmus) called ideal dmu (idmu) and antiidealdmu (admu) with fuzzy inputs-outputs, the efficiency evaluation of dmus are done by fuzzy dataenvelopment analysis (fdea). therefore, we evaluate dmus from the perspective of the best and worst possiblerelative efficiency. for each dmu two efficiencies are calculated while inputs and outputs are fuzzy.these two distinctive efficiencies are combined with the closeness coefficient (cc) index. the cc index isthen used for an overall ranking of all dmus. finally, we compare the result of proposed fuzzy dea modelwith león et al.’s (2003) results by representing a numerical example.