Among many other factors, they have to decide on the route, the loading capacity of the vans or trucks used and the extent to which they can be filled. Above all, they have to guarantee that delivery will be made before the deadline and at the estimated cost, in spite of traffic jams.
At present, this is a logistics problem that is too complicated to be solved using a formula that can be executed rapidly at a desktop computer. However, although it does not give the perfect answer, there is already an easy-to-use tool that offers logistics managers a way of finding a solution that improves on current formulas and lowers costs. This optimization system is described in the doctoral thesis of Miquel Àngel Estrada, PhD in Civil Engineering, lecturer at the Department of Transport and Regional Planning of the Universitat Politècnica de Catalunya (UPC) and research scientist at the Transport Innovation Center, which is run jointly by the UPC and the Government of Catalonia. The thesis has been awarded the fifth Abertis prize for Research on Transport Infrastructure Management by the Abertis Chair at the UPC.To reach the optimum solution, the system uses a tabu search-based metaheuristic algorithm, or in other words a group of operations that start by analyzing the present solution and go on to refine and improve it. The system defines the route, the size of the vehicles, and the location of the stopping points and then makes an estimate of the costs and chooses a strategy for sending the goods from three possible options.
The first option is to send them directly. The second is the multiple-stop or “peddling” option, in which the vehicle stops on the way, either to complete the original load or to deliver parts of it to different destinations. The third option uses load-transfer centers or hubs, which are storage centers where the trucks stop at unloading bays and the goods are taken out, redistributed and immediately loaded onto other vehicles at the loading bays.
The optimization system draws its conclusions on the basis of the variables involved. For example, the cost of handling goods in a hub affects the ideal-capacity calculations for the vehicles at the loading bays. The study demonstrates that small packages should be transported in large trucks when handling costs are low, whereas it is better to use vans, which fill up quickly, to transport these packages when handling costs are high.The method proposed by Miquel Àngel Estrada has been applied in situations in which the vehicles used are carrying full loads. In this case, it reduces costs by 7% compared with solutions proposed by other heuristic methods. The result is still better in cases of fractioned loads, for which the saving is of over 12%.
In addition, the new system calculates the extra costs incurred by delivery companies due to traffic congestion on the road network, and estimates that costs rise exponentially in areas where the traffic circulates at an average of less than 40 km/h for at least four hours a day.
THESIS: Analysis of efficient strategies in parcel-distribution logisticsWhy did you choose this subject for research?
Rossy Laciana | alfa
Variable speed limits could reduce crashes, ease congestion in highway work zones
07.06.2017 | University of Missouri-Columbia
Experiments show that a few self-driving cars can dramatically improve traffic flow
10.05.2017 | University of Illinois College of Engineering
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology