The Study On Vehicle Scheduling Model For Emergency Materials

A great deal of disaster-relief commodities are demanded to cure the wounded and take care of the victims when the calamity happens. So, the rescuers must solve the problem that how to make full use of the finite conveyance to transport disaster-relief commodities , such as drugs,medical treatment equipments,lifesaving equipments,foods,clothes,tents, so as to reduce the loss of disaster area to the lowest. As there are less existing researches , and the emergency situations are not considered enough, the vehicle scheduling of the emergency materials is needed to study further.The comprehensive overview for emergency logistics system is conducted in this article firstly, the concept of emergency logistics is proposed, the characteristics of logistics emergency are analyzed, and the establishment of emergency logistics systems and emergency logistic security mechanism are introduced. Meanwhile, the related problems of vehicle scheduling are analyzed, the introduction, classification, basic model as well as the basic solution of the vehicles scheduling problem are introduced and the constituent elements and objectives of scheduling problems are analyzed. On the assumption that the number of supplying materials is limited currently and in the future, the number of the current needs is known, and the number of the future needs can be predicted and on the assumption that the vehicles do not have to return to the inventory, emergency relief distributing vehicle scheduling model is constructed by using the method of plotting out time. The orders of scheduling vehicles are made up of a series of 'breakpoints' routes. The objective is to meet the maximization of the needs of rescue centers in the request time. The model can be decomposed of two network flow problems, Z1 is linear, the objective of which maximizes the demand of goods in the demand point, Z2 is an integer, the objective of which is to make the vehicles meet Z1 mostly. The two models are worked out by the method of Lagrangean Relaxation Iterative Algorithm. Finally , with the experiment and analysis for example, to validate the method's good convergence and efficiency. The researches above can provide scientific foundation for the government getting a reasonable vehicle scheduling when disaster happens.