Study On The Integration Of Production,inventory And Distribution Of Relief Supplies Based On Two-stage Method

The distribution centers provide a large number of relief supplies for the affected areas at different disaster stages during the emergency relief.The inventory of relief supplies in distribution centers can not often meet the needs of the affected areas,so it is particularly important to produce relief supplies reasonably to reduce the impact of disaster.Due to the blocked signal,road damage and so on in the affected areas,the number and capacity of vehicles of delivering relief supplies are limited.This thesis considers the limited vehicles' number and capacity in the affected areas and studies an optimally scheduling integrated problem of production,inventory and distribution of relief supplies.The works are summarized as follows:According to the single vehicle case in manufacturers and distribution centers,the integration problem of production,inventory and distribution is described firstly.The specific assumptions of the problem are made,and the parameters required for the problem are set and the decision variables of the problem are defined.Combined with the actual situation,a function is constructed about the time of vehicles which return to the manufacturer waiting for an order completed in the case of a single vehicle.Then a mixed integer programming model for the integration of production,inventory and distribution of relief supplies with single vehicle is established,aiming at the shortest production and delivery time.The idea of two-stage method is used in this thesis,and two interrelated divided sub-models are separately solved to obtain the optimal solution of the more complicated model.In the first stage,the sub-model is solved by improved genetic algorithm.And in the second stage,the other is solved by the implicit enumeration according to the solution obtained in the first stage.The algorithm is programmed by Matlab language,and the time complexity of two-stage method is analyzed.Finally,the effectiveness of the model and the algorithm is verified by one specific case.Furthermore,according to the multiple vehicles case in manufacturers and distribution centers,the description and assumptions of the corresponding problem are given.The parameters required for the problem are set and the decision variables of the problem are defined.A function is constructed about the time of vehicles which return to the manufacturer waiting for an order completed in the case of a multiple vehicles.Then a mixed integer programming model of integration of production,inventory and distribution of relief supplies with multiple vehicles is established.The model is also solved by the two-stage method.The algorithm is programmed by Matlab language,and the time complexity of two-stage method is analyzed.Finally,the effectiveness of the model and the algorithm is verified by one specific case.