Supply chain input and output

This study was conducted with the aim of evaluating the energy supply chain in the petrochemi-cal industry with the approach of Malmquist cost efficiency index and fuzzy VIKOR, taking into account the importance coefficient of input variables. After reviewing the literature, first the inputs and outputs of the energy supply chain were identified. Then, the influential variables in the petrochemical industry in the energy supply chain were identified and prioritized with the fuzzy VIKOR approach. Then the weight of the input variables was calculated with the geomet-ric mean and the input variables were entered into the mathematical model based on their weight. Based on input type, a mathematical model was written to estimate input costs to ensure output and supply chain efficiency in two consecutive years. Then the Malmquist cost index was estimated based on the model outputs. The petrochemical company with the highest Malmquist total cost index and the lowest output cost was selected as the optimal solution of the model. The value of the objective function indicates the input costs. Our inputs include two variables, the number of employees, the value of materials used in fuel reproduction. Petro-chemicals 9, 7, 12, 10, 6, 5, 3, 4, 13, 11, 2, 8, 1 and 14 respectively have the lowest input costs, but it is necessarily due to efficiency that petrochemicals and the efficiency of petrochemicals is checked. The cost return is calculated from the relevant formula in the years 2021 and 2022.