Research On Optimization Of China Railway Express Operating Plan Based On Service Network Design

At the national strategic level,China Railway Express(CR express)is regarded as an important starting point to promote "The Belt and Road" initiative,and at the local cities level,it is considered as an effective way to promote international trade and industrial upgrading.Since its operation in 2011,CR express has shown strong vitality and potential.Meanwhile,due to the lack of the overall coordination mechanism,the general problem and the special problem have arisen.The general problem is that as a mode of transport,the routes of CR express overlap seriously in transportation organization.The special problem is that the platform companies fall into disordered competition,because they each receives financial subsidies from the local government and represents the interests of the local government.As the chief participants in the operation of CR express,the platform companies are the crossing points that lead to the general problem and special problem above.Therefore,focusing on researching the platform companies and their unreasonable "point-to-point" operation mode may help to pinpoint the crux of the problems.The theory of service network design,which has been widely applied to the research on railway transport organization,is an effective method to study the optimization of CR express operating plan.With the detailed analysis of the basic theory of the service network and the operation plan of CR express,the paper designs the transportation service of CR express based on service network.According to the actual operation of CR express,an optimization model based on service network design is established,and a solving method based on Lingo software is designed,whose correctness are verified by an example network.On these bases,studying the existing CR express operation plan of main platform companies by modeling and solving,this paper obtains the optimized CR express operating plan efficiently.The optimized operating plan,which consists of optimized path plan and optimized service plan,can not only directly provide decision for OD flow distribution and express trains operation,but also indirectly obtain assembly center plan.Finally,the optimized operating plan is evaluated on levels of "overall network" and "each platform company" with the indexes of "timeliness" and "economy".The evaluation results show that:on the level of "overall network",compared with the existing operating plan,the optimized operating plan can help per container make the time in its whole journey reduce by 0.75 days and make the cost increase by 93 dollars.On the level of "each platform company",the time of per container belonging each platform company in the whole journey shortened.Although the cost is increased,the conversion value of the reduced time is greater than the increased cost.That is to say,the optimized operating plan is reasonable and feasible.In this paper,the lines of CR express has a wide coverage and strong representativeness.The optimized operating plan is confirmed to achieve synchronous optimization on both levels of "overall network" and "each platform company".In addition,with the optimized operating plan,we may obtain the assembly center plan synchronously,which realizes synchronous optimization of the operating plan and assembly center plan of CR express.This paper includes 19 figures,30 tables and 90 references.