Document Type: Article
Department of Industrial Engineering, Science and Research branch, Islamic Azad University, Tehran, Iran.
Department of Mathematics, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
Department of Management, Shahid Beheshti University, Tehran, Iran
Department of Industrial Engineering, Science and Research branch, Islamic Azad University, Tehran, Iran
Department of Mathematics, Science and Research branch, Islamic Azad University, Tehran, Iran
In this study, the multi-objective programming (MOP) method was used to solve network DEA (NDEA) models with assumption that, negative data is considered for the proposed NDEA model which consists of semi-negative and semi-positive input and output. At first, two stage and then k stage production models were formulated with consideration of negative data. In the multi-objective programming, two separate objective functions including the divisional efficiencies and the overall efficiency of the organization are modeled. In comparison to conventional DEA with negative data, the advantage of the proposed NDEA models is consideration of intermediate processes and products, in order to calculate the organization's overall efficiency. However, in conventional DEA, sub-stages of the organizations are neglected. To measure the efficiencies of an organization regarding interactive internal process, two case studies were investigated by application of the NDEA-MOP method with negative data. Case study 1 is focused on units with two stages having semi-negative and semi-positive indexes. In case study 2, units with three stages are evaluated. These units also have semi-negative and semi-positive indexes. The overall efficiency of each unit is calculated using the proposed models. Fuzzy approach as a solution procedure is applied.