Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering Transport Technology
A.M. Beeksma Groupage/degroupage in het goederenvervoer via tussendepots. Masters thesis, Report 94.3.LT.4248, Transport Engineering and Logistics.
In the distribution of goods from supplier to client it can be useful in some cases to make use of transshipment terminals. In this case large vehicles can be used for the transport of products from supplier to terminals. In the terminals the loads will be transshipped to smaller vehicles that deliver the products to the clients. We will call this a shuttle-system.
An important factor in this concept is the optimization of the assignment of loads to vehicles. By splitting the orders into smaller units, and regrouping them optimally, a distance saving and a mimimization of the number of vehicles could be achieved.
The purpose of this report is to investigate the possibilities to optimize the shuttle-system by splitting and regrouping orders. The optimization includes reduction of distance travelled and of the number of vehicles used. Because of the NP-hardness of the problem, heuristics are used.
The operational planning of the local vehicles has been improved by adapting the well-known savings-algorithm. Two different methods have been used to allow the splitting of client demands. The use of both methods showed a reduction in distance travelled and of the number of vehicles used.
The effect of minimizing the number of shuttle-vehicles has been investigated too. By re-allocating units to terminals the number of shuttles can be reduced. This will disturb the planning of the local vehicles however. The results of the tests show only a slight increase in distance travelled. However the influence of the environment is strong in this situation.
We can conclude that splitting client demands in a shuttle-system can be favorabie to other, unsplit algorithms. More research is needed however to fully benefit from the possibillities of splitting demands.
Combined with the optimization of the location of the terminals the splitting of demands can make the shuttle-system very competitive to pure pick-ip & delivery and distribution systems.
Reports on Transport Engineering and Logistics (in Dutch)
