VEHICLE ROUTING PROBLEM IN THE GREEN TRANSPORTATION CONTEXT

Thesis Overview

<p> 1. INTRODUCTION&nbsp;</p><p>&nbsp;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. <br></p>