The Research on Recovery Network Optimization of Medical Waste

Abstract

Medical waste is one of the major hazardous wastes. Not only the costs (distance) but security issue also should be taken into consideration when we build the recovery network of medical waste. Load-balance can decrease transportation risk efficiently. From this point of view, we formulate a vehicle routing problem with balance constraints (VRPBC), where both costs and transportation risk are considered, to minimize the total distance and make the loads among recovery vehicles balanced. The results of the model also tell managers the number of the recovery vehicles they need to arrange and their travel path.The model is solved by using improved genetic algorithm (GA). This method can avoid dropping into local optimum by adding reverse evolution operation after crossover operation. Finally, the real data is collected from Jinniu District of Chengdu and the results show that VRPBC model can balance the load among all the vehicles efficiently. When imbalance penalty is between 0.06 and 0.1, the loads in each vehicle are totally balanced and the total distance is only 9.15% above the solution produced by VRP model.