Improved model for strategic-loading-station location problem under incomplete information

In order to realize scientific planning the layout of strategic loading station, the strategic-loading station location problem was proposed, which is related to determine the location of each stay with station and the transportation plan on the precise of satisfying the general location constraints and problem related special constraints. Based on theory of capacitated facility location with multiple souring in two stage supply chain, one mixed integer linear programming model was established which took whole logistic cost embedding transportation and location costs as objective. When confronted with small and medium size problem, this model could be exactly solved by optimization software using branch and bound algorithm, and when the problem size was big, this model could be heuristically solved by genetic algorithm which used 0-1 and priority-based combined encoding method to represent solution, cost-based and random-generated combined method to generate initial solution, solution repaired strategy and penalty method and special fitness function to deal illegal individual, and greedy based method to heuristically solve transshipment problem. At last, according to computational tests on randomly generated data demonstrated the practical feasibility of this method. With the increasingly fierce market competition of various modes of transportation, building strategic- loading-station locations becomes an important measure to realize the innovation in organizing railway transportation of goods,which plays an important role in highlighting the advantage and market position of railway in the middle and long distance transportation of bulk cargo,achieving the centralization of transportation business, speeding up the speed of vehicles' turnover rate and the cargo's delivery, realizing the win-win situation between railways and shippers. Strategic- loading-stations is not only the key point of railway transportation system but also the cement between the feeders and cargo demanders.Scientific planning and management of their location, operation and other related issues is of great significance to speed up the construction of strategic- loading-station locations, fully play its advantages in cargo transportation, optimizing railway freight transport system and transportation organization mode. Strategic- loading-station location problem which determining the location of each stay that will be established, the transportation plans between strategic- loading-station and the cargo demand point and the transportation plans between strategic- loading-station and the cargo supply point is on the precise of satisfying the general location constraints and problem-related special constraints that are related to control the cost of entire logistics system. The problem of strategic-loading station location is belonging to the integer programming problem when it is considered in the model and it is belonging to the NP problem when it is considered in the algorithm theory. Based on it, this paper improves the model that it mentions to that the small and medium-sized actual problems can be solved by commercial optimization software directly and large-scale problems can be ensured efficiency by designing genetic algorithm based on the characteristics of the problem.