New approach in sensitivity analysis and identification of the region of efficiency for an efficient DMU

One of the topics of interests in data envelopment analysis (DEA) is sensitivityanalysis of specific decision making unit (DMU), which is under evaluation.Changes in inputs or outputs of any DMU can alter its classification, i.e. an efficientDMU become inefficient and vise versa. In this paper, we develop a newsensitivity analysis approach for obtaining the region of efficiency of an efficientDMU. In this region changes in inputs and outputs (inputs expansion and outputscontraction) of a DMU will not alter its efficiency status.