Research On Location-Routing Problem In Integrated Logistics Network Layout

With the tendency of global economy and the increasingly intense competition of marketing, enterprises focus their attentions on logistics of calling"the third profit source", and regard the improvement of logistics ability as the breakthrough of winning competitive advantage. The system is the prominent property of logistics. The business operation of realizing integrated logistic management is efficient, but the reasonable layout of logistics network is the preliminary to implement integrated logistics. In order to design high-efficient logistics network, location-routing problem (LRP) need to be resolved. LRP is the integration of location-allocation problem (LAP) and vehicle routing problem (VRP). The solution to LRP of combining the relativity of LAP and VRP can optimize the whole logistics system. The most of concerned researches on LRP is usually based on single-stage logistics chain network, is under demand circumstance with certainty, and takes no into account inventory control, but in this thesis, the research on LRP in the aspects is expanded to apply it to resolve more complicated layout problem of logistics network. Therefore, the fulfillment of the research will result in the optimum location of depots in the logistics network, the optimal routing of physical distribution, and the high-efficient logistics operation, and it is of significance for theoretical instruction of practical application in the layout of logistics network.Firstly, from the point of integrated logistics and in consideration of fuzzy demand, the model of the combined location routing and inventory problem (CLRIP) is presented for the single-stage logistics distribution network with multi-depot. CLRIP is used to allocate depots from several potential locations, to schedule vehicle routing to meet customers'demands, and determine the inventory policy based on the information of customers'fuzzy demands. A new heuristics algorithm is proposed to find the optimal solution for this model. A bi-level programming method is proposed to establish the model of CLRIP for the two-echelon distribution network in the supply chain. The upper level programming is to determine locations of depots to minimize location cost of logistics system. In the low level programming, scheme of vehicle routing and...