124 research outputs found
Advanced Planning Concepts in the Closed-Loop Container Network of ARN
In this paper we discuss a real-life case study in the optimization of the logistics network for the collection of containers from end-of-life vehicle dismantlers in the Netherlands.Advanced planning concepts like dynamic assignment of dismantlers to logistic service providers are analyzed by a simulation model.In this model, we periodically solve a vehicle routing problem to gain insight in the long-term performance of the system.The vehicle routing problem considered is a multi depot pickup and delivery problem with alternative delivery locations.We solve this problem with a heuristic based on route generation and set partitioning.Reverse logistics;Closed-loop supply chain mmanagement;vehicle routing;set partitioning;distribution planning
Closing Loops in Supply Chain Management: Designing Reverse Supply Chains for End-of-Life Vehicles.
In this thesis, the focus is on the design of reverse supply chains for end-of-life products, in particular end-of-life vehicles. For long-term success of end-of-life management, more economic stimuli are needed than is currently the case. Legislation as a single driving force is insufficient for companies to achieve closed loop supply chains. The key issue is to find eco-efficient solutions, i.e. design and operate an economically low cost network without violating applicable targets imposed by environmental legislation. In this thesis, a case study research methodology is adopted to develop design principles for network design and assess the consequences on the operations research models. Three case studies, which stem from the network of Auto Recycling Nederland, are described in detail.
Operations Research for Green Logistics – An Overview of Aspects, Issues, Contributions and Challenges
The worldwide economic growth of the last century has given rise to a vast consumption of goods
while globalization has led to large streams of goods all over the world. The production,
transportation, storage and consumption of all these goods, however, have created large
environmental problems. Today, global warming, created by large scale emissions of greenhouse
gasses, is a top environmental concern. Governments, action groups and companies are asking for
measures to counter this threat. Operations research has a long tradition in improving operations
and especially in reducing costs. In this paper, we present a review that highlights the contribution of
operations research to green logistics, which involves the integration of environmental aspects in
logistics. We give a sketch of the present and possible developments, focussing on design, planning
and control in a supply chain for transportation, inventory of products and facility decisions. While
doing this, we also indicate several areas where environmental aspects could be included in OR
models for logistics
Reverse logistics systems for waste generated throughout vehicles life-cycle
Waste produced during the service life of automobiles has received much less attention than end-of-life vehicles themselves. In this paper, we deal with the set up of a reverse logistics system for the collection and treatment of use-phase residues. First, the type of waste arising during vehicles? service life is characterized. Data were collected in collaboration with SIGRAUTO, the product stewardship organization in charge of vehicles? recovery in Spain. Next, three organizational models are proposed. The three alternatives are benchmarked and assessed from a double organizational and operational perspective for the particular case of the Madrid region in Spai
Metaheuristics for the waste collection vehicle routing problem with time windows, driver rest period and multiple disposal facilities
In this problem there is a set of waste disposal facilities, a set of customers at which waste is collected and an unlimited number of homogeneous vehicles based at a single depot.Empty vehicles leave the depot and collect waste from customers, emptying themselves at the waste disposal facilities as and when necessary.Vehicles return to the depot empty.We take into consideration time windows associated with customers, disposal facilities and the depot. We also have a driver rest period.The problem is solved heuristically.A neighbour set is defined for each customer as the set of customers that are close, but with compatible time windows. A procedure that attempts to fully utilise a vehicle is used to obtain an initial solution, with this initial solution being improved using an interchange procedure.We present two metaheuristic algorithms using tabu search and variable neighbourhood search that are based around the neighbour sets.We also present a metaheuristic based on variable neighbourhood tabu search, where the variable neighbourhood is searched via tabu search.Computational results are presented for publicly available waste collection problems involving up to 2092 customers and 19 waste disposal facilities, which indicate that our algorithms produce better quality solutions than previous work presented in the literature
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Metaheuristics for the waste collection vehicle routing problem with time windows
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.In this thesis there is a set of waste disposal facilities, a set of customers at which waste is collected and an unlimited number of homogeneous vehicles based at a single depot. Empty vehicles leave the depot and collect waste from customers, emptying themselves at the waste disposal facilities as and when necessary. Vehicles return to the depot empty. We take into consideration time windows associated with customers, disposal facilities and the depot. We also have a driver rest period. The problem is solved heuristically. A neighbour set is defined for each customer as the set of customers that are close, but with compatible time windows.
This thesis uses six different procedures to obtain initial solutions for the problem. Then, the initial solutions from these procedures are improved in terms of the distance travelled using our phase 1 and phase 2 procedures, whereas we reduce the number of vehicles used using our vehicle reduction (VR) procedure.
In a further attempt to improve the solutions three metaheuristic algorithms are presented, namely tabu search (TS), variable neighbourhood search (VNS) and variable neighbourhood tabu search (VNTS). Moreover, we present a modified disposal facility positioning (DFP), reverse order and change tracking procedures.
Using all these procedures presented in the thesis, four solution procedures are reported for the two benchmark problem sets, namely waste collection vehicle routing problems with time windows (VRPTW) and multi-depot vehicle routing problem with inter-depot routes (MDVRPI).
Our solutions for the waste collection VRPTW problems are compared with the solutions from Kim et al (2006), and our solutions for the MDVRPI problems are compared with Crevier et al (2007). Computational results for the waste collection VRPTW problems indicate that our algorithms produce better quality solutions than Kim et al (2006) in terms of both distance travelled and number of vehicles used. However for the MDVRPI problems, solutions from Crevier et al (2007) outperform our solutions.Ministry of Higher Education, Malaysi
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