H Saleh - Department of Mathematics, Central Tehran Branch, Islamic Azad University, Tehran, Iran
F Hosseinzadeh Lotfi - Department of Mathematics, Science and Research Branch, Islamic Azad University, Tehran, Iran
M Shafiee - Department of Industrial Management, Shiraz Branch, Islamic Azad University, Shiraz, Iran

Many papers have regressed non parametric estimate of efficiency in the two stage DEA procedure. All of these studies have several problems in the benchmark or projection unit and present the DMU with relative efficiency. Most of these papers do not present an efficient benchmark unit and cannot evaluate the relative efficiency unit. In this paper we review these studies and then create a two stage model that does not have these problems. Our model presents the efficient benchmark unit and also presents DMU with relative efficiency. In the next step we apply our two stage model in bank branches of a large commercial bank in Iran.

Data Envelopment Analysis (DEA), Efficiency, Two-stage