Model and algorithm for the multi-task routing optimization problem in 4PL

With the developing supply chain, fourth party logistics (4PL) has been attracting more and more attention from researches. Routing optimization is one of the important issues in 4PL. Based on the analysis of practical problems, considered the cost and time two properties of each node and edge, a mathematical model of the point to point multi-task without edge reuse routing optimization of 4PL is established. Considering the characteristics of the problem, the ant colony optimization (ACO) algorithm is designed for the problem. The algorithm is tested by numerical analysis with different scale of problems. The results suggested that the algorithm is effective and efficient.