الفهرس 
IntroductionOnly 14 pages are availabe for public view
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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 ...