Efficient surfaces and an efficiency index in data envelopment analysis: a constant returns to scale

Data envelopment analysis is an approach to assess the relative efficiency of organizations using multiple inputs to produce multiple outputs. The presence of strictly positive slack variables in DEA-model solutions causes computational and analytical problems. Efficient surfaces of production possibility set are found to be a useful tool in efficiency measurement. The present paper proposes a method for generating efficient frontiers in DEA problems. An application area investigated is that involving 20 bank branches within the branches of an Iranian commercial bank. The nature of returns to scale in this study is constant.