Managing of Cargo Flow in Logistic Service Networks coupled by Gateways

Background

The growing internationalization and a competitive environment are difficult challenges for transport services providers in road freight transport. Optimization of transport routes in logistic service networks thus becomes a more and more important issue. We want to find optimal sizes and locations for the gateways which are used to bundle and unbundle shipments on their way from source to sink. The (fixed) costs of these gateways have to be balanced with the prospective savings from using fewer trucks (due to load factor). As we look for a flexible routing mechanism, we get a huge number of possible routes and hence a computationally very difficult problem.

Procedure

The first aim of the project is to find and refine realistic models. Up to our knowledge, this is the first project that simultaneously considers:

• Vehicle based costs lead to a cost function in steps,
• The possibility of buffering shipments together with the integration of time slices and
• Different capacity levels in the gateways.

The resulting complexity overstrains commercial MIP solvers so problem-specific heuristic approaches have to be developed.

Together with the group „Discrete Optimization“ of the Faculty for Mathematics we especially develop methods that exploit the quadratic structure of the problem.

Targeted results

Heuristic approaches based on “Simulated Annealing” were successfully applied to the problem and existing solutions were vastly improved.

Results were published in “Electronic Notes in Discrete Mathematics” and presented at different conferences, especially “Verolog 2012”, “Verolog 2013” and “INOC 2013”.

Contact: Prof. Dr.-Ing. Uwe Clausen

Funding and partners

Prof. Dr. Christoph Buchheim
Chair of Discrete Optimization
​​​​​​​Department of Mathematics
TU Dort­mund Uni­ver­sity