Research On Optimization Methods For Remanufacturing Supply Chain Based On Option Contract Mechanism

In the 21^st century, sustainable development has become a topic of common concern for various countries in the world. Remanufacturing has been proposed as a modern manufacturing model for comprehensive consideration of environmental and resource efficiency. The new manufacturing model has been highly valued by governments and enterprises. With the successful implementation of remanufacturing, optimization problems of logistics network design and multi-item spare parts joint replenishment need to be solved. The present business environment is full of uncertainties. In order to effectively coordinate the relationship of entities in remanufacturing supply chain system, option contract mechanism is firstly introduced into optimization research on remanufacturing supply chain system in this dissertation.The total optimization objective of remanufacturing supply chain system is as follows: satisfing the conditions of forward product demand and reverse recovery and the optimal profit of the remanufacturing supply chain system. The optimization problem of remanufacturing supply chain system is composed of logistics network design problem and multi-item spare parts joint replenishment problem. According to product demands and recycled products, the optimization objectives of logistics network design problem are established to maximize the operating profit of logistics network, minimize the environmental influence and maximize customer satisfaction level. It determines the quantities, locations and distributions of facilities in remanufacturing supply chain system. The optimization objective of multi-item spare parts joint replenishment problem is established to minimize inventory cost. New spare parts are replenished and waste spare parts are recycled with group replenishment.Compared with the traditional supply chain system, remanufacturing supply chain system should consider forward logistics for products distribution, and consider reverse logistics for recycling of waste products. For research on the remanufacturing supply chain system with uncertain environment, the wholesale price mechanism is generally used to approximately determine product market demand, and basic optimization model of remanufacturing supply chain is developed. For the insufficiency of the wholesale price mechanism in uncertain environment, remanufacturing supply chain system is effectively coordinated and controlled by option contract mechanism in the dissertation, and optimization models based on the option mechanism of remanufacturing supply chain are developed.During a specific time period, dual-uncertain factors of product market demands and recycled waste products are considered in remanufacturing supply chain system. The optimization objective for single-period remanufacturing supply chain logistics network is as follows: maximize the operation profit of logistics network, minimize the environmental influence and maximize customer satisfaction level. Option contract mechanism effectively controls uncertain product market demands. Multi-objective optimization models based on the option contract mechanism are developed. According to the characteristics of models, dual-layer genetic algorithms are developed to solve the optimal values. Finally, numerical examples illustrate the validity of the models and algorithms for the optimization problem.In the multi-period remanufacturing supply chain system, we should consider continuity, repeatability and otherness of product market demands and recycled waste products at each period. The optimization objective for multi-period remanufacturing supply chain logistics network is as follows: maximize the total operating profit of logistics network, minimize the total environmental influence and maximize total customer satisfaction level. Option contract mechanism effectively controls uncertain product market demands at each period. Multi-objective optimization models for multi-period logistics network based on the option contract mechanism are developed. According to the characteristics of models, dual-layer hybrid genetic algorithms are developed to solve the optimal values. Finally, numerical examples illustrate the validity of the models and algorithms for the optimization problem.In remanufacturing supply chain system, we consider the forward supply process and the reverse recycling process. The dissertation proposes a fixed-cycle inventory replenishment strategy based on the option contract mechanism. The optimization strategy model for stochastic spare parts joint replenishment problem is developed with replenishment strategy based on the option contract mechanism. According to the characteristics of models, immune genetic algorithm is developed to solve the optimal values. Finally, numerical examples illustrate the validity of the model and algorithm for the optimization problem.