“…The use of this theory in DEA can be traced to Sengupta (). According to Hatami‐Marbini, Emrouznejad, and Tavana (), DEA approaches using fuzzy theory can be classified into four primary categories: (a) parametric approaches that convert a fuzzy DEA model into a parametric model depending on a parameter α level (Kao & Liu, ; 2000 b; ; Razavi, Amoozad, Zavadskas, & Hashemi, ; Zadeh, Firozja, & Erfani, ; Zerafat Angiz, Emrouznejad, & Mustafa, ); (b) possibility approaches that represent fuzzy variables by probability distributions (Lertworasirikul et al, ; Wang, Chuang, & Tsai, ); (c) ranking approaches, with the main objective of designing a fuzzy DEA model able to yield fuzzy efficiencies that can be ranked using different methods (Jahanshahloo et al, ); and (d) defuzzification approaches that try to first convert fuzzy values of inputs and outputs into crisp values then to solve the resulting DEA crisp model (Juan, ). Many other approaches have also been introduced to fuzzy DEA development (Wang et al, ; Zerafat Angiz, Emrouznejad, & Mustafa, ).…”