Calculation of the Efficiency of Two-Stage Network Structures with Additional Inputs to the Second Stage by SBM Approach: A Case Study on Credit Branches of an Iranian State Bank in Guilan Province

Many studies have been conducted to determine the efficiency of two-stage network structures in the recent years. The two-stage network with additional inputs to the second stage, in which the second stage is independent of the first stage are one of these structures. Thus, there is a need for a model capable of calculating the efficiency of two-stage structures as well as efficiency of each stage which can then provide managers with recommendations to increase the efficiency of the entire system and its sub-processes. In this study, a non-cooperative game adapted from game theory and SBM approach is used to calculate the efficiency of a two-stage network structure to provide a unique analysis of the overall efficiency as the product of efficiency scores of the two stages. SBM approach is a non-radial DEA model capable of providing modification recommendations for inputs and outputs. The model then is implemented on 29 credit branches of an Iranian state bank in Guilan province and the results are analyzed.