VEHICLE ROUTING PROBLEM IN THE GREEN TRANSPORTATION CONTEXT
Table Of Contents
Thesis Abstract
<p>ABSTRACT</p><p>
In the efficient management of the supply chain the optimal management
of transport of consumables and finished products appears. The costs
associated with transport have direct impact on the final value consumers
must pay, which in addition to requiring competitive products also demand
that they are generated in environmentally friendly organizations.
Aware of this reality, this document is intended to be a starting point for
Master’s and Doctoral degree students who want to work in a line of
research recently proposed green routing. The state of the art of the
vehicle routing problem is presented in this paper, listing its variants,
models and methodologies for solution. Furthermore, the proposed
interaction between variants of classical routing problems and
environmental effects of its operations, known in the literature as GreenVRP is presented. The goal is to generate a discussion in which
mathematical models and solution strategies that can be applied within
organizations that consider within their objectives an efficient and
sustainable operation are posed.
KEY WORDS Heuristics for the vehicle routing problem, vehicle routing
problem, Emission estimation techniques, green transportation
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Thesis Overview
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1. INTRODUCTION </p><p> Today the world population is nearly 7 billion people and is projected to
reach 9 billion by 2040. An important component of the middle class
population is characterized by its size and the high requirement level of a
variety of resources. According to forecasts, this segment of the population
will increase by 3.000 million in the next 20 years, which will increase the
use of the requested resources exponentially.
In 2012, the Panel on Global Sustainability of the United Nations (UN)
drew attention to an important fact: The world requires ensuring their global
needs. These needs are essentially water, food and energy. There is
however one aspect of great relevance overlooked and that is related to
the ongoing pursuit of social welfare: mobility. The little planned road
infrastructure and uncontrolled vehicles incorporating this infrastructure,
growth leads humanity to a global gridlock. To date has nearly 2000 million
vehicles, according to Ford projections, in 2040 will be 4 billion. 75% of the
world population will live in towns and cities there will be about 50 to more
than 10 million.
Global gridlock directly affects the quality of life of city dwellers. The
proposed solution to this problem necessarily pass through aspects such
as: 1) Service Management (solid waste collection, definition of emergency
routes, logistics distribution plans and gathering); 2) supply chain (transport
of inputs and goods); 3) urban transport planning and 4) transportation of
workforce serving various support services, such as in the case of gas
companies, electricity and water supply. A distribution company as well as
public transportation company requires managing their fleet supported by a
set of associated equipment and services.
The problem of transport of goods, commodities and people is as relevant
as when it was raised in 1959 by Dantzig and Ramser (1959), where it was
considered as a generalization of the traveling salesman problem. The first
article in which the phrase “Vehicle routing” appeared is attributed to
Golden et al (1972) ). Other versions of Vehicle Routing Problem (VRP)
appeared in the early 70s. Liebman and Marks (1970) presented
mathematical models that represent routing problem associated with the
collection of wastes; Levin (1971) posed the problem of fleet vehicles;
Wilson et al. (1971) presented the problem of telephone request for
transportation service for persons with disabilities and Marks and Stricker
(1971) presented a model for routing public service vehicles. Some
probabilistic concepts were associated with the problem by Golden and
Stewart (1975). In Solomon (1987) constraints of time windows were
included; Sariklis and Powell (2000) proposed a problem where the vehicle
does not return to the point where the journey begins. Recently, some
specific conditions have been added to approach VRP to real life
problems, resulting in several variants which modify constraints or the
objective function of the basic VRP optimization model.
The purpose of this paper is to present the state-of-the-art of VRP
considering it is an important supply chain element. Separate the problem
into categories, considering different situations, mathematical models and
solution techniques. In addition a review of the techniques used in the
calculation of fuel consumption and the way to involve it to the VRPs,
which has led an interesting area of research Green-VRPs.
The paper is organized as follows: In section 2 the importance of
transportation in the supply chain is presented. Next, in section 3 the VRP
is classified. The mathematical models are described in section 4. Further,
the solution techniques are listed in section 5. An overview of emission
estimation techniques is shown in section 6. Finally trends and future
directions in Green VRP are presented in section 7.
2. IMPORTANCE OF TRANSPORTATION IN THE SUPPLY CHAIN
In recent years, consumers, businesses and governments have increased
their attention to the environment. Society is more aware of the
environmental damage caused by human activity and is more concerned
about the indiscriminate use of natural resources. A growing interest is also
seen by companies to reduce the environmental impact of their products
and services (Quariguasi et al., 2009).
The chain management “green” supply has been defined as:
[…] the integration of environmental thinking within the
administration of the supply chain, including design, selection of
sources of raw materials, manufacturing processes and product
delivery end consumers as well as the administration of the
products when they end their life. (Srivastava, 2007,p. 54)
Interest in this area has increased significantly in business, for employees
of organizations, governments and benefits companies looking to
implement “green” supply chain , including cost reduction, improved
product and process quality, risk reduction and improving financial
performance (Vachon and Klassen, 2008; Sarkis, Zhu and Lai, 2011).
With regard to the environment, transportation is one of the most visible
within the supply chain aspects. The amount of carbon dioxide (CO2)
emissions from transport is calculated at 14% of total emissions. Transport
is also the main source of nitrogen dioxide (NOx), sulfur dioxide (SO2) and
other particles (McKinnon and Woodburn, 1996). The results of studies of
the most important factors for emissions of carbon dioxide (CO2) in road
transport are presented in Piecyk (2010).
United States has established standards for NOx, SO2 and PM for trucks
based on the standard Euro V, regulated by the European commission,
and that is part of a package of measures adopted by the European
Parliament in 2007. According to the results studies, the trucks are much
cleaner for the environment than most ships and trains. Offshore vessels
emit large amounts of NOx. It is estimated that these emissions exceed the
total emissions from land transport unless action is taken there on Dekker,
Bloemhof and Mallidis (2012).
Transportation modes (e.g. Airplane, boat, truck, train, barge or pipeline)
have different characteristics in terms of cost, transit time, accessibility and
environmental performance. In Leal and D’Agosto (2011) a method for
selecting the mode of transport, applied to the transport of bio-ethanol in
Brazil is presented, this is an adaptation of the methodology called MCM
(The Modal Choice Method). Some questions to be addressed in the
“green” supply chain are: how much does it improve the environment? How
to balance environmental concerns and profitability in business? The socalled eco-efficient solutions show that additional efforts are required to
improve the quality of the environment.
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