Zahra Noori - Department of Mathematics‎, ‎Islamic Azad University‎, ‎Lahijan Branch‎, ‎Lahijan‎, ‎Iran.
Hamed Zhiani Rezai - Department of Mathematics‎, ‎Islamic Azad University‎, ‎Mashhad Branch‎, ‎Mashhad‎, ‎Iran.
Alireza Davoodi - Department of Mathematics‎, ‎Islamic Azad University‎, ‎Neyshabur Branch‎, ‎Neyshabur‎, ‎Iran‎.
Sohrab Kordrostami - Department of Mathematics, Islamic Azad University, Lahijan Branch, Lahijan, Iran

Data envelopment analysis models are able to rank decision-making units (DMUs) based on their efficiency scores‎. ‎In spite of the fact that there exists a unique ranking of inefficient DMUs‎, ‎ranking efficient DMUs is problematic‎. ‎However‎, ‎rather than ranking methods‎, ‎another way to choose one of the efficient units is to determine the most efficient DMU‎. ‎Up to the present‎, ‎many models have been proposed to rank DMUs and determine the most efficient one‎. ‎These models require solving nonlinear or integer programs‎, ‎which are NP-hard and time-consuming‎. ‎Considering efficient DMU's characteristics‎, ‎this paper proposes a procedure to find the most efficient DMU through some simple operations‎. ‎The validity of the proposed approach is verified and tested via some numerical examples.

Data envelopment analysis‎, ‎Most efficient DMU‎, ‎Input and output weights‎, ‎Mathematical model