Provide a model for calculating the efficiency of companies with the help of network data envelopment analysis with undesirable factors

Each steel company buys the raw materials it needs from the manufacturers in question, thus forming supply chains with network properties. Therefore, there is a need to conduct performance research to improve the performance of these chains. In studies, the study of specific structures in the supply chain has received less attention. In this research, we have tried to examine the network and how to evaluate its performance in the presence of uncontrollable, undesirable factors. For this purpose, network DEA models are proposed that evaluate the performance of the chain in the presence of uncontrollable inputs and outputs, undesirable output even in its internal structure. Then, 11 present steel companies, the corresponding chain of each of which has two stages, were evaluated by the presented models in 1398. The designed model was based on the network Data Envelopment Analysis of tailored the companies under study and their efficiency was calculated. Based on the results, one company under the first stage and one company under the second stage were recognized as efficient, and all companies had a total efficiency of less than one.