The motivation of this paper is to propose such equitable method for ranking all decision making units (DMUs) in dynamic Data Envelopment Analysis (DDEA) framework. As far as we are aware there is not more studies in dynamic DEA literature. What's more, in such cases the best operating unit is important to be sampled for the others in under evaluated time periods. However, in this special concept of DEA, quasi-fixed inputs or intermediate products are the source of inter temporal dependence between consecutive periods. Hence, in order to have suitable ranking for units operating in dynamic environment the minimum and maximum efficiency values of each DMU in dynamic state are computed. Also, we assume that the sum of efficiency values of all DMUs in dynamic state is equal to unity. Thereafter, the rank of each DMU is determined through the combination of its maximum and minimum efficiency values. A real case of Iranian gas companies highlights the applicability of the proposed method in Dynamic framework. Manuscript profile

Data envelopment analysis (DEA) has been proven as an excellent data-oriented efficiency analysis method for comparing decision making units (DMUs) with multiple inputs and multiple outputs. In conventional DEA models, it is assumed that the input or output variables are all non-negative and desirable. However, in some situations, a performance measure can take positive quantity for some DMUs and negative value for others. Also, undesirable (bad) inputs and outputs may be presented in the production process. Hence, the standard model cannot directly reflect the efficiency score. The paper proposes a modified model in which both undesirable and negative data are treated to improve the relative efficiency of the DMU under evaluation. The focus of this paper is on treating the negative data on the definition of the two non-negative variable and the decreasing of undesirable outputs. A real example of 20 bank branches shows applicability of the proposed approach Manuscript profile

The importance of environment protection always raises a considerable among the researchers especially when pollutant and undesirable outputs are present. The non-parametric Data Envelopment Analysis (DEA) literature on network-structured performance analysis normally fail to express the undesirable intermediate production in the process. From the production efficiency point of view, symmetrically handling both of the desirable and the undesirable outputs in the assessment process in the two stage network structure is developed in this paper. The motivation of this study is the application of the directional distance function (DDF) to modeling the two-stage network structure with the undesirable intermediate measures upon employing Stackelberg theory. A real case on the thirteen poultry units in Iran has been illustrated to verify the applicability of the proposed approach. Manuscript profile

Data envelopment analysis (DEA) as a non-parametric method has covered a wide range of applications in measuring comparative efficiency of decision making units (DMUs) with multiple incommensurate inputs and outputs. The standard DEA method requires that all input and output variables be known as semi positive. In many real situations, the presence of undesirable and even negative data are inevitable. In DEA literature there have been various approaches to enable DEA to deal with negative data. On the other hand, the structure of interval data has recently attracted considerable attention among DEA researchers. According to importance of interval data, this paper proposes a radial measure which permits the presence of undesirable and negative data with interval structure. The proposed model can evaluate the efficiency of all DMUs and leads to improve the inefficient unit with interval negative and undesirable data. To elucidate the details of the proposed method an illustrative example of a private bank in IRAN explores the applicability of the proposed method. Manuscript profile