@article { author = {Khorshidvand, Behrooz and Soleimani, Hamed and Seyyed Esfahani, Mir Mehdi and Sibdari, Soheil}, title = {Sustainable closed-loop supply chain network: Mathematical modeling and Lagrangian relaxation}, journal = {Journal of Industrial Engineering and Management Studies}, volume = {8}, number = {1}, pages = {240-260}, year = {2021}, publisher = {Iran Center for Management Studies}, issn = {2476-308X}, eissn = {2476-3098}, doi = {10.22116/jiems.2020.215206.1330}, abstract = {This paper addresses a novel two-stage model for a Sustainable Closed-Loop Supply Chain (SCLSC). This model, as a contribution, provides a balance among economic aims, environmental concerns, and social responsibilities based on price, green quality, and advertising level. Therefore, in the first stage, the optimal values of price are derived by considering the optimal level of advertising and greening. After that, in the second stage, multi-objective Mixed-Integer Linear Programming (MOMILP) is extended to calculate Pareto solutions. The objectives are include maximizing the profit of the whole chain, minimizing the environmental impacts due to CO2 emissions, and maximizing employee safety. Besides, a Lagrangian relaxation algorithm is developed based on the weighted-sum method to solve the MOMILP model. The findings demonstrate that the proposed two-stage model can simultaneously cope with coordination decisions and sustainable objectives. The results show that the optimal price of the recovered product equals 75% of the new product price which considerably encourages customers to buy it. Moreover, to solve the MOMILP model, the proposed algorithm can reach to exact bound with an efficiency gap of 0.17% compared to the optimal solution. Due to the use of this algorithm, the solution time of large-scale instances is reduced and simplified by an average of 49% in comparison with the GUROBI solver. }, keywords = {Sustainable Closed-loop Supply Chain,pricing,Lagrangian Relaxation}, url = {https://jiems.icms.ac.ir/article_133512.html}, eprint = {https://jiems.icms.ac.ir/article_133512_7563f7b5d31318d27ea7859b27836d54.pdf} }