Study On Logistics Centers' Location By Combining Bi-level Programming And Dynamic Programming

With the rapid growth of economy, the improvement of living standard and the diversification of consumer demand, trade and circulation of commodities become prosperous, thus the logistics industry comes into being; the development of commodity consumption market and the gradually speeding up of storage turnover rate cause many problems, such as the rise in the cost of logistics, urban traffic congestion and environmental pollution etc. The emergence of logistics center, as a node of logistics system, can alleviate these problems. The decision-making of logistics centers'location directly affects the logistics cost and service efficiency. As a result, this paper carries through system of theoretical analysis and case studies for the logistics centers'location. Specific work is as follows:First of all, based on reading vast literatures, this paper points out the problems of location methods, model and solving. It also analyzes the common methods of logistics centers'location, and this paper focuses on the basic theory and application of bi-level programming and dynamic programming theory.Secondly, to research of logistics centers'location during multi-programming-period, the paper establishes logistics centers'location model by combining bi-level programming and dynamic programming. Through adding bi-level programming model of restriction of client's time constraints, it can achieve the balance between customer satisfaction and the cost of both the logistics center and clients. This paper also introduces dynamic programming model of the transfer costs and risks of default payment, which educes optimal dynamic location strategy during multi-programming-period, which's closer to the actual circumstances.Thirdly, this paper designs the process of solving problems according to the established logistics centers'location model. At first, by using time-series single-index moving method, this paper forecasts the customer requirement of each phase during programming period. Then it uses MATLAB7.0 programming to achieve the result of bi-level programming model. In the end, this paper gets the optimal location by contradictorily getting the result of dynamic programming model.Finally, this paper makes case analysis by adopting the data provided by a productive enterprise. It validates the effectiveness of the established logistics centers' location model and provides evidence of decision-making in logistics centers'location of that enterprise.