A comment on a new super-efficiency model in the presence of negative data

In a recent paper by Hadi-Vencheh and Esmaeilzadeh (VE), a super-efficiency model based on the range directional model (RDM) is formulated to establish a complete ranking of decision-making units (DMUs). The authors prove that their proposed Model is feasible and bounded.. But, the critics, Jafar Pourmahmoud, Adel Hatami-Marbini, and Elnaz Babazadeh, show that the VE Model suffers from the common infeasibility and unboundedness problems and cannot produce the numerical results claimed. They prove it by providing several theorem and equations.