Robust Optimization Model Design And Simulation Of Closed-loop Supply Chain Under Uncertain Environment

With the rapid development of global economy,the natural resources in the world are diminishing,the public awareness of environmental protection is also gradually increasing,so the closed-loop supply chain emerges,arousing widespread concern in business and academia.The closed-loop supply chain management has become a major trend in the future development of enterprises.While compared with the forward supply chain,the closed-loop supply chain covers many reverse logistics activities such as product recycling,maintenance,remanufacturing,and reusing.And with more complex network structure,the closed-loop supply chain has its inherent characteristics of high uncertainty,disturbed by uncertain factors from the internal operation and external environment,directly affecting the normal operation of the closed-loop supply chain.Therefore,it is of great significance to manage and control the impact of these uncertain factors on the closed-loop supply chain operations.This paper uses the method of robust optimization to research the closed-loop supply chain operations under uncertain environment.We establish several robust optimization models under the uncertainty of product demands,raw material supplies,as well as prices of products and raw materials and implement the system based on the above models.The paper provides a research method to reduce and eliminate the influence of uncertainty on the capabilities and strategies of closed-loop supply chain operations.The supply chain coordination,the profit maximization of manufacturers and suppliers are considered as operational objectives in the multi-objective robust optimization models.The main research work of this paper is as follows:Firstly,the robust optimization model of closed-loop supply chain under the uncertainty of product demands and raw material supplies is studied.We use discrete scenarios with known probabilities to describe the uncertainty of demand quantity for products and supply quantity for raw materials.The multi-objective robust optimization model under uncertain demand and supply is established using the robust optimization method based on scenario analysis.A numerical example is given to verify the robustness of the proposed model.Second,the paper studies the robust optimization models of closed-loop supply chain under the uncertainty of product prices as well as the uncertainty of prices for products and raw materials.We use continuous symmetric interval to represent uncertain prices of products and raw materials.The robust optimization method based on interval analysis can be used to deal with the effects of uncertain prices on the performance of supply chain operations.Furthermore,numerical examples are designed to verify the robustness of the two models.Third,the simulation of robust optimization model system is studied.Based on the above robust optimization models,we design the key algorithm of the system and realize the system function.Finally,the robust optimization model system is used to conduct an empirical research of the closed-loop supply chain,which shows that the system can support the decision of production operation under uncertain environment.