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.‎ پرونده مقاله

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.‎ پرونده مقاله

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. پرونده مقاله

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. پرونده مقاله

Two of the essential and important topics of scholars' research are congestion and classification in Data Envelopment Analysis. There are lots of papers that researchers represented their methods in these fields separately. Assume that there is a different method that can predict the congestion of Decision Making Units. In this paper, we represented our method that predicts the congestion of DMUs instead of calculating their congestion. The advantage of this method is for the time that measured the congestion of DMUs but we need to add new DMUs and we do not want to calculate the congestion of all DMUs again. For this reason, we define available DMUs into three groups such as DMUs with strong congestion, DMUs with weak congestion, and DMUs with no congestion; then predict the congestion of new DMU. In the last section, we represent the numerical example of our purpose method. The result shows that the prediction of congestion is so correct. پرونده مقاله

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. پرونده مقاله

A line location problem as a subdivision of facility location problem deals with finding a straight line in the plane, so that sum of weighted distances or maximum weighted distances from the line to the demand points is minimized. This paper provides a novel approach to study the semi-obnoxious median line location problem with Euclidean norm by using data envelopment analysis method. Since the presented procedure would consider lines as decision making units, so efficiency of lines is taken into account instead of their optimality. Moreover, due to the inherent uncertainty of the parameters of the line location problem in the real world such as weights or/and coordinates of demand points, the problem under interval data is studied in viewpoint of data envelopment analysis as well. Furthermore, some propositions and a numerical example are provided to investigate the problem. Finally, conclusion is given. پرونده مقاله

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. پرونده مقاله