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Abstract The concept of vehicle routing problems became one of the most important and powerful business concepts for organizations in order to compete in today’s global market place. To effectively manage a logistic system, efficient design of the vehicle route should be established. The present work addresses the design of vehicle routing problems, taking into consideration the different aspects related to such a design. During the last decades, much effort has been devoted to the area of vehicle routing problems. Researchers have produced extensive literature in this field. Many of the issues related to the vehicle routing have been considered separately in these entire designs. Such issues are for example imposing time window limitations on customer’s time frame, solving the problem with a fixed number of vehicles and having a heterogeneous fleet of vehicles. A comprehensive review of literature has been illustrated to provide an overview of the previous research in this field. It has been concluded that researchers have mostly addressed these different issues separately, and rarely have considered the previous issues altogether. The main objective of this current work is constructing a tabu search metaheuristic model that treats the limitations in the previous models and considers all the previous issues in a single model, in addition to comparing the developed model to other heuristics from the literature and applying it to an industrial case study. The proposed Two-Phase Tabu Search Metaheuristic (T-PTSM) model for the heterogeneous fixed fleet vehicle routing problem with time windows covers the limitations of the previously developed models and considers the practical application to real world cases. The proposed T-PTSM model is deterministic and static. It is assumed that all information relevant to the planning of the routes is assumed to be known before the routing process and does not change after the routes have been constructed. The model has the objective of eliminating the number of routes and minimizing the total costs, including the travelling cost and the vehicles fixed costs. The constraints include demand constraints, time window constraints and fleet constraints. The model addresses scheduling related characteristics by taking into consideration the service time at each customer. The T-PTSM model also provides an answer to many strategic decisions in a vehicle routing problem design. These decisions include number of vehicles, capacity of vehicles and sequence of customers to be visited in a route. The proposed model was solved using Microsoft Visual Basic package that uses a visual basic codes to solve different instances of the problem in a reasonable of time. The verification and testing of the model was done using a test model and twenty benchmark instances from literature developed for the heterogeneous fleet vehicle routing problem with time windows, the benchmark problems are adopted here to solve the same problem but with a fleet of a fixed number of vehicles. The T -PTSM model successfully passed all verification tests and its ability to deal successfully with large problems sizes was proven. The T-PTSM model was compared to different models from literature and has shown improved results in several benchmark problem instances. Finally, the T-PTSM model was implemented in a real world case study for an industrial company that provide waste management services. In this case study, the company is planning routes for waste collection in different regions based on experience. It is required ... |