Network design in sustainable closed loop supply chain

In this study, a closed loop supply chain for determining strategic decisions attempting to optimize simultaneously economic, environmental and social effects of sustainability is designed. Recommended closed loop supply chain is developed by using goal programming techniques and considering to make social utility maximum while keeping costs and environmental damages to minimum. Decision variables number of workers, aiming to employ workers in social effects of sustainability are integrated into developed model. Moreover, a new model is created by assessing 3 basic rings of sustainability within themselves and weighing them with FAHP (Fuzzy Analytic Hierarchy Process) methods. The effects of the developed method under different conditions are examined building a scenario analysis. The model's effects on parameters set as "capacity", "demand", "cost", "carbon amount" and "variable of labour force" are analysed. It is seen that "demand variability", "costs", "the quantity of products that one worker can transfer" and " variability of facilities' capacity" are the most effective parameters on decision variables which are defined on the model in accordance with the results of scenario analysis. It is concluded that the most demanded result expected from the parameters is reducing the costs by % 30. Keywords: Closed loop supply chain network, Sustainability, Mixed integer modeling, Goal programming, FAHP