Fuzzy Location-Routing-Inventory Problem In Recycling Medical Waste

With the rapid development of economy and the people's living standard, the department of medical treatment has got the fast development in our country. More and more complicated medical wastes were produced by the medical institutions, including the infectious medical waste and non-infectious medical waste. If we can not disposal and recover them well, not only the environment and human health would be brought a great hazards, but the resource of recycle would be lost. However, medical waste is not recovered and disposed normatively in our country. Disposal of recycling medical waste involves a series of work, including the collection, separation, recovery, processing and so on. In order to promote efficiency of the whole system, it's necessary to make integrated optimization and management from the perspective of system optimization.Medical waste recycling process itself is a logistics system. The following problems shall be settled when optimizing and managing the systems:first, the choice of medical waste disposal (recycling)center location; second, the optimization of recovery path in the medical waste recycling process; third, the inventory control of medical waste disposal(recycling)center. The above three problems correspond respectively to the three key factors of the logistics systems optimization:facilities location, vehicle routing arrangement and inventory control. With more and more attention drawn to the integration and optimization of these factors, now many researchers focus on the integration of two factors, such as the location-routing problem(LRP), inventory-routing problem(IRP),etc. But in fact, it is necessary for us to research the integration and optimization of the three factors, namely location-routing-inventory problem(LRIP), because the intrinsic link among them is also very important.In this paper, in the background of recycling medical waste, we divide the research into two aspects according to the characteristics of recycling medical waste.One is the location-routing-inventory problem in the recycling infectious medical waste and the other is the location-routing-inventory problem in the recycling non-infectious medical waste. For infectious medical waste, considering the risk of hazardous materials, a multi-objective location-routing-inventory problem (LRIP) with fuzzy volume of recyclable waste is developed to minimize the total system cost and transportation risk. For non-infectious medical waste, according to the characteristics of recovery, a model of location-routing-inventory problem with fuzzy volume of recyclable waste is established to minimize the total system cost. According to the characteristics of the model, a two-phase heuristic algorithm is proposed, and a numerical example is given to illustrate the effectiveness of the model and methods, also a result of sensitivity analysis of parameters is given in the end.