Performance evaluation of two stages network with undesirable outputs and weak disposability

Production and service systems include multiple stages. Network data envelopment analysis is a method that is commonly used in the evaluation of multi stage system. These stages can be classified as independent, relationship, and cooperative modes. In the real world, the presence of undesirable indicators is unavoidable in systems, and are important in the performance evaluation of processes. In this study, some models are presented with types of stage relations in the system, in the presence of undesirable data, and under the assumption of weak disposability. Air transport is one of the multistage systems, which the cost and speed of change in the transportation industry confirm the necessity of evaluating its performance in competitive world. We evaluated performance of airlines using the proposed models from both internal and external perspectives, also we considered delay in airlines as undesirable factors in air transport. The results revealed the efficient performance of seven Iranian airlines of the fourteen considered airlines in the relationship, cooperative, and independent states, and from both internal and external perspectives. Also, Iran Air and Meraj companies acted efficiently only in the cooperative (specified) state.