Kobra Gholami - Young Researchers and Elite Club, Bushehr Branch, Islamic Azad University, Bushehr, Iran
Zahra Ghelej Beigi - Department of Mathematics, Mobarakeh Branch, Islamic Azad University, Esfahan, Iran

Data Envelopment Analysis (DEA) is a non-parametric approach for measuring the efficiency of a set of Decision Making Units (DMUs), in which any DMUs consume multiple inputs to produce multiple outputs. One of the topics of interests in DEA is sensitivity and stability analysis of the cost efficiency classifications related to DMUs. This paper provides some stability intervals for preserving the cost efficiency classifications based on conventional DEA models. Changing input or output values of each DMU can alter the cost efficiency classifications of DMUs. That is a cost efficient DMU might become inefficient and vice versa. In this paper, we obtain stability intervals for all DMUs corresponding to costefficiency classifications. Numerical examples are presented to illustrate the applicability of the proposed method.

Data Envelopment Analysis, Decision Making Unit, Cost Efficiency, Sensitivity Analysis