International Mathematical Forum, 2, 2007, no. 64, 3191 - 3198 DEA Efficiency Analysis with Identifying Efficient and Full-Inefficient Frontier G. R. Jahanshahloo a , M. Zohrehbandian b , F. Hosseinzadeh Lotfi a 1 M. Ghadimi b , M. Ahadzadeh Namin a and M. Hokkamzadeh b a Department of Mathematics, Science & Research Branch Islamic Azad University, Tehran, Iran b Department of Mathematics, Islamic Azad University P.O. Box 31485-313, Karaj, Iran Abstract Data envelopment analysis (DEA) is a mathematical programming technique for identifying relative efficiency scores of decision making units (DMUs). Recently, Amirteimoori (2007) Introduced an alterna- tive efficiency measure based on efficient and anti-efficient frontiers. In this paper we introduce a new computational framework for identifying full-efficient and inefficient frontier of production possibility set (PPS) in DEA models with variable return to scale. This facets apply in find- ing full-efficient and inefficient DMUs, sensitivity and stability analysis, ranking, and etc. Keywords: Data Envelopment Analysis; VRS, Efficient frontier, Full- inefficient frontier 1 Introduction Data envelopment analysis(DEA), originally proposed by Charnes, et al. (1978), has became one of the most widely used methods in management sciences. DEA is a non parametric technique for measuring and evaluating the relative efficiency of DMUs which stand of decision making units with several inputs and outputs. Classical DEA models rely on the assumption that inputs have to be minimized and outputs have to be maximized.The performance of a DMU depends only on the identified efficient frontier characterized by the DMUs with an unity efficiency score. The efficiency of a DMU is a scaler 1 Corresponding author. e-mail: hosseinzadeh lotfi@yahoo.com