Research On The4PL Earliness/Tardiness Routing Optimization Problem

Logistics makes valid flow and the plan of inventory from supply points to the demand points, implements and controls the entire process, which are to meet consumer’s demand for raw materials, inventory, product and relevant information. With the intensify of market competition, the need of reducing logistics costs has led to the logistics providers must treated the logistics services at a higher perspective, and upgrade of previous supply chain management to integration of supply chain and redesigning of solution, so The Fourth Party Logistics (shorted for4PL) emerged.In research of the4PL, the routing optimization problem is the key issue. The4PL routing optimization problem involves the entire supply chain optimization and the choice of the Third Party Logistics (3PL) providers and so on. In order to reduce the corresponding penalties for breach of contract, the4PL provider must ensure delivery on schedule as well as satisfying the customer’s transport schemes, so this paper further study on the4PL earliness/tardiness routing optimization problem according to analyzing the research and application of the4PL routing problem both in this field. Therefore, this issue has important theoretical and practical significance.In view of the characteristics of the4PL routing problem, based on the reviews of the modeling and optimization methods of4PL routing problem and on the considering the earliness/tardiness problems of logistics distribution, the paper firstly dscribes the constraints such as time, capacity, credibility in the light of multigraph, then establish the mathematical model of single-point to single-point single-task routing optimization problem of4PL, and designs Traversal algorithm, Heuristic algorithm and Improved Ant Colony algorithm. Comparison of simulation shows that these algorithms could respectively solve the problem in different size, and among them, the Random-PSO algorithm based on traversal included in Heuristic algorithm is the predominant. Then, in terms of the multigraph, the model of single-point to multi-point single-task routing optimization problem of4PL is established. Meanwhile designs Traversal algorithm, Ebedded Random-PSO Heuristic algorithm based on arrangement and priority-based selection strategy simplified method respectively under the scale of the problem, and the simulation experimental results show that these methods are effective and feasible. This program is helpful to the reality of logistics operation.