Research On Transport Service Procurement Of Single Carrier And Single Shipper Based On Bilevel Programming

With the rapid development of the economy and the continuous refinement of the social division of labor,most manufacturing enterprises usually outsource the delivery service to the third party logistics enterprises in order to focus on the limited time and resources to develop their core competitiveness,which resulting in the problem of transportation service procurement.Transportation service procurement is defined as the process of obtaining transportation services from external resources market according to its own transportation demand.Its decision is the first step of cost and quality of service in the process of logistics outsourcing.The success of decision results directly affects the effect of logistics outsourcing cooperation.In the process of transportation service procurement,the logistics service enterprise,as a carrier,needs to choose a number of transportation services to offer a quotation.The transportation service which is chose reasonably can not only gain large income,but also make full use of its own logistics capacity to achieve the purpose of integrating logistics resources.The manufacturing enterprise which is a shipper,as well as a buyer of transportation service activities should decide whether to cooperate with the carrier according to the quotation of the carrier.The carrier hopes to gain more profit from the transportation service,while the shipper wants to get the transport service at the lowest price.It can be seen that both sides have contradictions and mutual cooperation in the purchase price,and there is a clear stratified structure in the decision making.As a result,the bi-level programming theory is suitable for it.According to the different performance of the carrier and the shipper in the transportation service procurement,the bi-level programming model of the transport service procurement by the single carrier and single shipper is set up on the basis of the mutual relationship between the two parties.In order to be closer to the real decision process,the carrier is the decision-maker of the upper level planning model,and the shipper is the lower level planning decision-maker,seeking the relatively optimal state of both the carrier and the shipper.When the carrier adds the route to the original transportation network,it is not only to meet the original distribution task,but also to satisfy the new distribution task.The vehicle path planning is the first problem to be solved.The carrier needs to make a reasonable distribution scheme to make the maximum profit.Therefore,the vehicle routing constraint is added to the upper levelplanning model.The related constraints of the vehicle path planning.In the aspect of solving the model,first of all,according to the characteristics of the model,the transport route is divided into three types,and the discrete particle swarm optimization(PSO)is used to solve the problem.Secondly,the binary particle swarm optimization(PSO)algorithm is designed to solve the overall bi-level programming model.In order to verify the rationality of the model and the effectiveness of the algorithm,two numerical examples are analyzed in this paper,which shows that the proposed model and algorithm can solve the problem of transport service procurement of single carrier and single carrier,and further elaborate the theory of this paper.