A Multi-scenario Robust Optimization Model For Freight Express Service Network Design

At present, railway freights transportation is in the critical period of the development of logistics transformation. In the context of the’China’s New Normal’, competition in the transport market is very severe. It has the higher requirements with the speediness, security, reliability, convenience and so on. In order to meet the needs of shipper, to suit development of e-commerce logistics, freight express service network, as a new railway freight product, has great research value. Under this background, this thesis studies the designing of the railway freights transportation service network.First of all, this thesis analyzes the basic theory of rail freight network. First, in order to make clear the research contents, this thesis discusses the freight express market demand, besides, according to the 95306 website gives the current railway freight transport system for the railway express freight classification. Second, sum up the railway freight express service of seven factors and correspond to the manifestations and solutions. Third, this thesis analyzes the form and process of railway transportation organization. In addition, the operation process of railway freight transportation is analyzed. Fourth, this thesis put forward the design principles and objectives of railway freights transport service network, as well as the main contents of design of railway freights transport service network, which is to determine the transportation service path, stop schedule plan and marshalling plan.Secondly, this thesis constructs a deterministic model of railway freights transportation service network and a multi-scenario robust optimization model for freight express service network. This is the key content of this thesis. On the one hand, the total transportation cost is divided into three parts:fixed cost, transportation cost and delay cost. On the other hand, the concept of structure model is freight flow. It considering full of the transfers and train detaching and attaching in the construction. In order to make the research more practical, this thesis constructs a multi-scenario robust optimization model for freight express service network design. The objective function of the summation about degree of scene deviation is used. The total goal is not only to meet the minimum total cost of railway operations, but also to consider the stability of the model in reality.Moreover, an intelligent algorithm-harmony search algorithm (HS) is put forward in this section considering the solving the complexity of large-scale road network under the railway freights transportation service network design problem. More specifically, two stage models, which are feasible solution generation steps, are designed respectively used to determine the type of railway freights transportation service network model and a multi-scenario robust optimization model for freight express service network design in order to get the better initial harmony memory (HM), which improves the convergence speed of the algorithm effectively. Based on the solving process of the two models, this thesis verifies the effectiveness of the model and algorithm with an example. This proves that the transport cost can be calculated more accurately considering the results of the robustness.Finally, through a real example, the model and algorithm’s effectiveness are verified, which provides a valuable reference for railway freights transportation service network design.