Flexibility of Variations in Radial and Non-Radial Data Envelopment Analysis ‎Models

One of the major problems in Data Envelopment Analysis (DEA) is to determine the projection of inefficient Decision Making Units (DMUs) into the efficient frontier. In conventional DEA models, inputs and outputs of inefficient DMUs alter arbitrarily for reaching to the efficient frontier. Nevertheless, sometimes the ability of DMUs is defined and restricted. Moreover, there are situations in the real world applications that limited resources exist. Therefore, in these cases inputs and outputs cannot vary irrationally. Actually, there are pre-specified alteration levels of inputs and outputs. For this purpose, the current study proposes DEA-based models, radial and non-radial models, to evaluate the relative efficiency of DMUs with restricted input and output variables. Furthermore, non-radial super-efficiency models are extended for ranking efficient DMUs. An example from the banking sector is used to illustrate the proposed approach.