Undesirable Output such as pollution and waste may occasionally occur in the production process, which should be reduced to improve efficiency. In the present study, cost efficiency model is presented in the presence of undesirable output by Inverse Linear Programming, and the desirable cost is calculated in order to achieve cost efficiency for units that are technically efficient but not cost-‎efficient.‎ Manuscript profile

This paper deals with benchmarking for a three-stage DMU. After investigating and eliminating congestion, adjustment of intermediate products and initial inputs have achieved by utilizing an Inverse DEA model, which dominates the current vectors and serve as a benchmark that is to the best of this paper knowledge. This process has two cases. First, the overall efficiency stays fixed, and the second case, is corresponded to the overall efficiency ‎improvement.‎ Manuscript profile

This manuscript extends the CSW model to stochastic inputs and outputs. Next, the stochastic CSW model is transformed into a nonlinear model, and then, the deterministic model is transformed into a quadratic programming model. Finally, the concept presented in this article is demonstrated through a numerical example involving a number of Iranian banks. Manuscript profile

In this paper we propose FNDEA models based on the multiplier model under constant returns to scale (CRS) and variable returns to scale (VRS) in general two-stage network structures to classify flexible measures, in which each one of the flexible measure is treated as either input or output to maximize the overall network efficiency of the DMU under evaluation. Manuscript profile

In conventional DEA methods, all inputs and outputs are assumed to be continuous. However, the implied presumption of continuous data may not maintain an acceptable level of precision in practical data. Many practical situations such as number of teachers in a school, number of students in a college, or research papers only take integer values. Presented work presumes subsets of input and output variables in traditional five-pronged axioms in DEA model to be integer values for the first time in the field. An additional effort in this work expands axioms and a new model is presented. This paper presents a novel two phase model that in the first phase produces more precise efficiency values and the best benchmark in its second phase, i.e. the nearest integer point to the efficiency boundary is selected based on constant returns to scale. A case study is presented that demonstrates a comparison of efficiency values obtained with this model compared to prior models that is show in table 1. And in Table 2, the values of the slack are compared with each other. Manuscript profile

Border points of the production possibility set (PPS) have particular importance in data envelopment analysis (DEA). The present study aims to provide a method to find weak defining hyperplanes of DEA models by the anchor points. Anchor points are an important subset of the set of extreme efficient points of the PPS in DEA. They are directly related to weak defining hyperplanes in the production possibility set. Therefore, we used this feature and offered a practical algorithm to find weak defining hyperplanes of PPS. Eventually, we illustrate our algorithm using two numerical examples. Manuscript profile