Research On Transportation And Inventory Integrated Optimization Based On Materials Of Project For International Rail Construction

With the deepening of the strategy of "the Belt and Road Initiatives" in China,China's rail transit technology,especially the increasingly perfect high-speed rail technology,more and more domestic enterprises to join the construction of international rail transit projects,and further strengthen the projects fine management,especially at present China's major rail transit industry chain "going out",The materials and equipment required by the project are from domestic procurement,transport to the project construction site of the destination country,effectively reducing the inventory cost and transportation cost in the logistics cost is the general trend,and can further strengthen the competitiveness of China's engineering projects.This article based on the current large-scale state-owned enterprises in the main EPC contract to build the international track project,and China's external rail projects more and more use of Chinese equipment,the use of systematic,integrated thinking will have a "benefit back" phenomenon of the inventory cost and transportation to take into account,The joint optimization model of inventory transportation is established.The objective function of the model is composed of fixed order cost,storage cost,out-of-stock cost,shipping cost,domestic transportation fee in destination country,and vehicle usage fee to analyze the joint optimization problem of multi-stage inventory transportation,and the decomposition-coordination algorithm and the improved genetic algorithm are used to solve the model.To solve the problem of premature convergence and searching ability of classical genetic algorithm,if the selection of chromosome encoding,genetic operator,fitness function,control parameter and so on is unreasonable,it will lead to premature or late convergence,or the search out solution is not the global optimal solution,which is a local optimal solution,this paper presents an improved genetic algorithm,An improved scheme is proposed for the selection operator,crossover operator and mutation operator in genetic algorithm,and the result shows that the improved scheme greatly improves the iterative efficiency of genetic algorithm and can search the global optimal solution more efficiently.Finally,taking an international urban rail project as an example,this paper verifies the combined transportation and inventory optimization model and algorithm,compared with the logistics cost of the current project,the result shows that adopting the idea of joint optimization can reduce the logistics cost and save the social resources.