* Corresponding author E-mail: khaoula.ouaddi@gmail.com (K. Ouaddi) 2020 Growing Science Ltd. doi: 10.5267/j.ijiec.2020.4.001 International Journal of Industrial Engineering Computations 11 (2020) 643–662 Contents lists available at GrowingScience International Journal of Industrial Engineering Computations homepage: www.GrowingScience.com/ijiec Memetic algorithm for multi-tours dynamic vehicle routing problem with overtime (MDVRPOT) Khaoula Ouaddi a* , Fatima-Zahra Mhada a and Youssef Benadada a a Mohammed V University in Rabat ENSIAS, Morocco C H R O N I C L E A B S T R A C T Article history: Received February 5 2020 Received in Revised Format February 28 2020 Accepted March 5 2020 Available online March 5 2020 After three decades of its introduction, the dynamic vehicle routing problem (DVRP) remains a fertile field for new studies. The technological evolution, which continues to progress day by day, has allowed better communication between different actors of this model and a more encouraging execution time. This encouraged researchers to investigate new variants of the DVRP and use more complicated algorithms for the resolution. Among these variants is the multi-tour DVRP (MTDVRP) with overtime (MTDVRPOT), which is the subject of this article. This paper proposes an approach with a memetic algorithm (MA). The results obtained in this study are better than those of the ant colony system (ACS) applied to the same problem and published in an earlier paper. © 2020 by the authors; licensee Growing Science, Canada Keywords: DVRP Memetic algorithm Multi-tours Overtime 1. Introduction Dantzig and Ramser (1959) introduced a wide class of problems, the objective of which is to determine the best roads linking two or more points under certain constraints. Since then, many researchers have studied different possible variants of this problem. These variants are defined depending on the nature, constraints, and objectives of the problem. In the classical version, the objective is to determine the optimal set of routes that should deliver to a set of customers from a single depot with a limited fleet of trucks with limited capacities. These customers have varying demands for the same products. Golden et al. (1977) introduced the term ‘vehicle routing’ and called this variant ‘the generic vehicle routing problem’ (VRP). By imposing that the delivery to each customer is accomplished in a limited time window, a new VRP variant namely, VRP with time window was introduced by Solomon (1983). If there are several depots at which the trucks begin their tours, the multi-depot VRP is used, which was introduced by Kulkarni and Bhave (1985). If the fleet of trucks is inhomogeneous, the heterogenous VRP (HVRP) is employed, which was introduced by Golden et al. (1984). Thus, researchers have defined and treated a large number of VRPs according to the demands of the transport market and ability of the technological context (Eksioglu et al. (2009)).