With regard to environmental pressures and economic benefits, some original construction equipment manufacturers, have focused on collecting and recovering construction machinery at the end of their life. The present study aimed to focus on Sustainable closed-loop supply chain network optimization for construction machinery recovering. To this purpose, different recovery options such as remanufacturing, recycling and reusing were implemented. A mixed integer linear programming model (MILP) including three objective functions was proposed in this regard. Based on the model, all three dimensions of sustainability including economic, environmental, and social dimensions were considered and could successfully determine the optimal values of the flow of used products, remanufactured products, recycled parts, re-usable parts. In order to demonstrate the applicability of the proposed model, a numerical example was used with the help of GAMS software to obtain the supply chain structure with the lowest cost and reduce the pollution caused by CO₂. Finally, the model could maximize fixed and variable job opportunities.

中文翻译：

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工程机械回收的可持续闭环供应链网络优化

考虑到环境压力和经济效益，一些原始建筑设备制造商已经集中精力收集和回收使用寿命结束的工程机械。本研究旨在关注工程机械回收的可持续闭环供应链网络优化。为此，实施了不同的回收方案，例如再制造、回收和再利用。在这方面提出了包括三个目标函数的混合整数线性规划模型(MILP)。基于该模型，可持续发展的三个维度包括经济、环境和社会维度都被考虑在内，并且可以成功地确定废旧产品、再制造产品、回收零件、可重复使用零件的流动的最优值。₂ . 最后，该模型可以最大化固定和可变的工作机会。