32 research outputs found

    Report on Effect of Several Light Truck Defenders in Indian Subcontinent

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    The exterior design of the vehicle and other internal components, such as the deflector attached to it, play a major role in aerodynamics. It has been noted that large numbers of light trucks without any aerodynamic features are produced and operated in the Indian subcontinent. The primary objective of this study is therefore to analyze the impact of aerodynamic devices or rails in Bangladesh and Pakistan on light-duty trucks. The study consisted of computer modeling, quick physical models manufacture and wind tunnel testing including CFD analysis. Nonetheless, in the Indian subcontinent, particularly in Bangladesh, India and Pakistan, there are as yet a critical number of light trucks that are operational that is made by changing a Bedford J arrangement truck Analyzed and compared the drag forces produced by each model. The results show that aerodynamically efficient deflectors for most locally produced Bangladeshi and Pakistani trucks can improve the overall aerodynamic drag by up to 22 per cent. The aerodynamic fitting can reduce fuel consumption by 12 percent by replacing these deflectors

    A Review on Quantitative Approaches for Dock Door Assignment in Cross-Docking

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    Cross docking is a relatively new technique in supply chain operations. It offers limited storage time to maximize the efficiency of goods transshipment. Efficient operation of a cross docking system requires an appropriate coordination of inbound and outbound flows, accurate planning and dynamic scheduling.  The planning strategies at cross docking terminals, which are receiving growing attention today, are the truck-to-door assignment and destination to door assignment problems. This paper provides a comprehensive literature review of quantitative approaches in dock door assignment problems of cross docking planning. The contributions of this paper are to identify the gap of knowledge in operational levels mainly in dock door assignment and to point out the future research direction in cross docking

    Design und Betrieb von Cross Docks

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    Die hohen Anforderungen an heutige Wertschöpfungsnetzwerke in Bezug auf Flexibilität und Lieferbereitschaft stellen die Distribution vor die Aufgabe, Güter immer häufiger und in immer kleineren Mengen ausliefern zu müssen. Ein Ansatz, diesen Forderungen auf möglichst wirtschaftliche Art und Weise gerecht zu werden, besteht darin, bestehende Distributionsnetze um sogenannte Cross Docks zu erweitern. In solchen lagerlosen Umschlagzentren können dann kleine Warensendungen mit ähnlicher Destination zu vollständig ausgelasteten Lkw-Transporten konsolidiert werden, um sogenannte "economies in transportation" realisieren zu können. Neben den strategischen Überlegungen für und wider die Einführung von Cross Docks stehen in diesem Aufsatz insbesondere die Planungsprobleme im Mittelpunkt, die es im Rahmen der Errichtung und der täglichen Prozessabläufe in einem Cross Docking Terminal zu lösen gilt.

    Dock Assignment and Truck Scheduling Problems at Cross-docking Terminals

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    In this paper, we consider the integration of dock assignment and truck scheduling problem at cross-docking terminals. The problem is first formulated as a 0-1 integer programming model. Since both dock assignment and truck scheduling problems are NP-hard, its integration is more difficult to solve. Thus we propose reduced variable neighborhood search (RVNS) algorithms to solve the problem. Computational experiments are carried out on four set of instances. The results show that RVNS is capable of finding good solutions in a much shorter computation time when it is compared with optimization solver Gurobi’s solutions

    Integrating workload smoothing and inventory reduction in three intermodal logistics platforms of a European car manufacturer

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    We consider the optimization of container loading at three intermodal logistics platforms (ILP) of a large European car manufacturer (ECM). The decisions focus both on the loading day of each container and on its filling with the products in inventory, which are gradually received over the week from inland suppliers. The objective is either to reduce the largest inventory level needed in the ILP, or to smooth the weekly workload. We develop a solution methodology that allows the handling of complex loading constraints related to dimensions and weight of the products. We model the problem as a mixed integer linear program and we develop a decomposition heuristic to solve it. We perform extensive computation tests on real instances provided by ECM. Compared with current industrial practices, our solutions yield an average improvement of 46.8% for the inventory reduction and of 25.8% for the smoothing of the workload. Our results highlight the benefit of jointly optimizing container loading and operations scheduling.</p

    Inbound and outbound flow integration for cross-docking operations

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    We consider the optimization of the cross-docking operations at three INtermodal LOgistics Platforms (INLOPs) of a large European car manufacturer (ECM). The planning horizon is a week and the time bucket is a day. An inbound flow of products is gradually received over the week by truck from inland suppliers, and has to be loaded into containers which are then shipped to offshore production plants. The full content of a container must be available at the INLOP to enable its loading operations to start, hence temporary storage is needed. The objective is to minimize an inventory penalty, computed as the largest daily volume of temporary product storage observed over the planning horizon. The current practice at ECM is to first optimize the content of the inbound trucks and of the outbound containers independently, and then determine the loading day of each container to be shipped based on these fixed contents. We propose to integrate, within the same optimization framework, the decisions on both truck and container contents, which involve complex loading constraints related to the dimensions and weights of the products, with those on the scheduling of container loading. We model the resulting problem as a mixed integer linear program, and we develop a decomposition scheme for it, as well as a fix-and-optimize matheuristic. We perform extensive computational experiments on real instances provided by ECM. Results show that a combination of these two matheuristics is able to generate solutions that reduce the average inventory penalty by 40%.</p

    Model of dynamic allocation of storage places in Cross Docking centers

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    Este trabajo describe una metodología para la asignación de lugares de almacenamiento temporal en centros tipo Cross Docking, para lo cual se desarrolla un modelo cuyo principal aporte es la asignación dinámica de productos entrantes a estos lugares de almacenamiento. El modelo minimiza los costos asociados al inventario final de los productos y los costos asociados a las distancias recorridas por unidad de carga. Se logra, además, una reducción del tiempo de permanencia y una aceleración del flujo de los productos desde la recepción hasta el despacho. Como principal conclusión, se identifica la importancia de las asignaciones puerta a puerta, en la reducción de los costos.This paper describes the methodology applicable to temporary storage in Cross Docking centers using a mathematical model. This model favors the dynamic allocation of storage places to incoming products in Cross Docking centers, reducing the costs associated with the final inventory of each of the products and the costs associated with the distances covered by each load unit. It also achieves a reduction in the time of permanence and an acceleration of the flow of products from reception to dispatch
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