DYNAMIC AND NETWORK SBM MODELS

Current data envelopment analysis (DEA) models which are suggested for calculating the efficiency of decision making units (DMUs) are quite limited models, in the sense that these models do not consider sub-DMUs and middle activities at different times, while today, in the real world, long term investment, temporal designs in the presence of middle activities is one of the issues that managers deal with repeatedly. These designs are changed to models with dynamic network structures. To this end, in this study, models are suggested to evaluate dynamic network efficiency based on the SBM model. In order to distinguish the relationships between sub-DMUs, there are two classifications employed: free and fixed and to distinguish the relationships between times, there are four classifications: free, fixed, desirable, and undesirable. Also, in addition to calculating overall efficiency, the proposed model can calculate the efficiency of sub-DMUs one by one at different times.