关键词: 再制造供应链, 双重不确定性, 生产批量, 采购批量

Abstract: The recycling, remanufacturing and reselling of parts is of great significance for the resource conservation and reduction of environmental burden. For example, the first batch of 14 remanufacturing pilot enterprises announced by the National Development and Reform Commission, such as WEICHAI Power (Weifang) and Sino-Trunk, have started to calculate the economic cost of the whole remanufacturing supply chain of waste engines and other parts and arranged remanufacturing production in combination with demand orders. Meanwhile, in August 2022, the National Development and Reform Commission, the National Bureau of Statistics and the Ministry of Ecology and Environment jointly issued the Implementation Plan on Accelerating the Establishment of a Unified and Standardized Statistical Accounting System for Carbon Emissions, proposing that a unified and standardized statistical accounting system for carbon emissions would be initially established by 2023. Therefore, this study provides decision-making reference for enterprises to formulate remanufacturing production batch strategy and procurement batch strategy under double uncertainty.
In this paper, the remanufacturing supply chain consists of procurement, transportation, storage and manufacturing activities. Considering the uncertainty of the annual demand quantity of the end market and the uncertainty of the quantity of remanufactured parts in the recycling market, and taking each production batch and purchase batch in the remanufacturing process as the decision variables, a baseline model is established for the annual environmental cost, annual economic costs, and annual total costs of the entire remanufacturing supply chain system. The following problems are studied: (1)By solving the model, the existence of the optimal production batch and purchase batch is discussed respectively when the annual environmental cost, annual economic cost and annual total cost are the lowest. (2)The expression of the optimal production batch and purchase batch is calculated, and the optimal production decision of the enterprise is demonstrated by a numerical simulation experiment. (3)Through a sensitivity analysis, the influence of the double uncertainty of market demand and the quantity of remanufactured parts on the optimal production batch and purchase batch is discussed.
The results show that: (1)Under the three situations of the lowest environmental cost, economic cost and total cost, there is a unique optimal production batch and purchase batch and an increase in the proportion of remanufacturable parts can significantly reduce the annual total production cost. (2)When remanufacturable parts or new parts are in two different preparation states of finished products and products in process, differences in corresponding annual carbon emission, annual economic cost and annual total cost significantly affect the production batch and purchase multiple strategies of enterprises. (3)The double uncertainty of remanufacturable parts and consumption demand quantity will have different effects on the optimal solution. When the total storage cost generated by the storage unit of finished products in the finished products warehouse is greater than the total storage cost generated by the storage unit of supporting parts required for the preparation of finished products in the parts warehouse, with an increase in the proportion of remanufacturable parts, the optimal production batch will decrease and the optimal purchase multiple will increase. With an increase in the total market demand, the optimal production batch will increase, and the optimal purchase multiple will decrease. When the total storage cost generated by unit product storage in finished product warehouse is less than or equal to the total storage cost generated by corresponding supporting parts required for unit product preparation in parts warehouse, the purchase batch should always be equal to the remanufacturing production batch. In this case, the optimal production batch will increase with an increase in the proportion of remanufacturable parts or the total market demand. And the optimal purchase volume will be increased simultaneously to achieve the minimum annual total cost.
This study has enriched the relevant research on the remanufacturing supply chain in the waste recycling-manufacturing-consuming market. In the future, combining the classification of the quality characteristics of remanufactured parts, we can try to discuss the remanufactured production decision-making of recycled parts with different quality levels. We gratefully acknowledge the financial support from the National Natural Science Foundation of China (No. 72172112).

Key words: remanufacturing supply chain, dual-uncertainty, production batch, order quantity