Improved Solution of VRPSPD with the Tabu Search Algorithm

The development of transportation has a significant impact on economic systems, both production and service, which makes the vehicle routing problem a special issue, one of the most important decisions in executive departments is to pay special attention to finding optimal routes, eliminating unnecessary routes, improving the distance traveled and reducing the number of fleets. In this regard, it is one of the complex and very important problem in the transportation network, this problem has a high potential in determining the optimal set of vehicle fleets with the aim of serving a set of customers, which many efforts have been made to solve it. Various meta-heuristic algorithms have been developed in recent years, one of them is the tabu search algorithm because it has good performance and ability to solve NP-Hard problems, and now in this article, the tabu search algorithm is used to solve the vehicle routing problem with simultaneous pick-up and delivery of goods which by applying some changes in its coding in MATLAB software. Determining the parameters of the repetition value of the algorithm, specifying the number of neighborhoods and the amount of the tabu list improved the results obtained in the distances traveled by vehicles and optimized the number of fleets. Finally, the new proposed algorithm was implemented on 14 standard sample problems from the Salhi and Nagi series of problems, and the obtained values were compared with the best available results from other algorithms, which had satisfactory results in small-scale problems..