Study Of Production Decision And Material Planning Oriented To OEMs Closed-loop Supply Chains

Diminishing resources, overflow waste sites and increasing levels of pollution tell us that our environment is escalating deteriorating. These issues have captured the attention of industries, governments and academia. In many countries, the laws and regulations that force Original Equipment Manufacturers to take back and recycle used products are already in place or in the works. OEMs are discovering it to be a profitable approach while at the same time expending their responsibility. As a result, more and more OEMs focus on reuse of products obtained via the reverse material flows in closed-loop supply chains. The main product recovery business they are engaged in is remanufacturing, which is ranked as the best form of product recovery.Including remanufacturing, production system is significantly different from conventional manufacturing production system. Instead of single forward flow of material in conventional supply chains, closed-loop supply chains are characterized by both the forward and backward materials flows. OEMs contend with some factors that limit the effectiveness of traditional methods of production planning and control. Developing a new set of production and control activities is needed.This paper addresses the planning problem of OEMs'closed-loop supply chains management. The characteristics of the hybrid manufacturing/remanufacturing production system are discussed first to distinguish its new requirements. The production planning system oriented to OEMs closed-loop supply chains is put forward. It integrates all the planning and scheduling activities involved in production system.The role and task of production decision is similar to Master Production Scheduling. In this paper, the remanufactured items and new items are the same to the customers. A new approach using chance-constrained programming is discussed to solve the problem of production decision. There are two different situations. One is that OEMs have the right to decide whether to procure used products from the brokers and how many used products will be procured, the other is that OEMs are forced to accept all the used products from consumers. Therefore, two different models are constructed. In the first model, the demand and the amount of used products the brokers can offer are considered as uncertain random variables. Both the demand and return of the production system are uncertain random variables in the second model. Genetic algorithms combining random simulation are given to solve the models.The thought of MRP can still help with material planning. In addition to conventional BOM, two new BOM are used to calculate dependent demand, namely BOM for remanufactured products and BOM for remanufacturable products. Using chance-constrained programming and genetic algorithm, a disassembly plan oriented to demand is presented, considering uncertain yield and partly disassembly. In order to examine its effectiveness, a simulation experiment compares this model with related deterministic programming. The result is good as expected.