Multi-level Closed-loop Supply Chain Quality Control Under Contract Coordination

With the promotion of environmental awareness,the rational recycling of waste products has become one of the key points of the research on quality control of closed-loop supply chain,and the recycling of products is the main measure of closed-loop supply chain management,which can not only reduce the production cost of products,but also improve the efficiency of nodes and the overall system in the closed-loop supply chain.It also reduces the resource consumption of processed raw materials and the emission seist of used products,which can help improve the environmental performance of each node.Because of the uncertainty and complexity of closed-loop supply chain system,it is difficult to study the quality control problem of closed-loop supply chain.This paper uses contract coordination to study,through the method of system dynamics to establish a four-level closed-loop supply chain quality control model and contract coordination of quality control model,to enhance the closed-loop supply chain members at all levels and the overall profit efficiency.Firstly,this paper studies the impact of four-level closed-loop supply chain quality control on members at all levels and overall profits.Through Vensim software,the causal loop diagram of four-level closed-loop supply chain quality control is plotted and the relationship between the influencing factors and the model boundary are analyzed.By entering the equations between the variables,the system flow diagram and model of fourlevel closed-loop supply chain quality control are established,and the rationality and authenticity of the model are tested.Secondly,the quality reward and punishment contract model,the quality cost allocation contract model,the recycling contract model and the combination contract model are established.The influence of contract parameters on system synergy in the process of contract implementation is studied.By establishing a coordination mechanism for contractual parameters,the coordination effect is improved and the profits of members at all levels are enhanced.Through numerical simulation,the change trend of the overall profit of each contract member and closed-loop supply chain is obtained.Finally,in view of the real problems,the introduction of W automobile manufacturing company.Establish a four-tier closed-loop supply chain portfolio contract model of suppliers,retailers and recyclers with partnerships with the company.By comparing the model with the individual contract coordination model,it is found that the profit maximization of members at all levels of the four-level closed-loop supply chain can be achieved under the coordination of the combination contract.At the same time,it can promote the overall profit performance of the closed-loop supply chain of auto parts to improve the profit efficiency compared with the coordination of single contract.