Vehicle routing with integrated 3D loading optimization (Partner: WITRON Logistik + Informatik GmbH)
WITRON Logistik + Informatik GmbH plans, implements and operates tailor-made logistics and material flow systems. It also offers the integrated industry solution CPMS (= Corrugated Packaging Management System), which supports all value-added processes in the corrugated board industry. The functionality also includes transport planning and shipping.
Loading optimization at WITRON
The aim of the project is to improve WITRON's existing vehicle routing solution. It is necessary to consider complex transport tariffs and various practical restrictions for the vehicle routing problem, e.g., several time windows, order splitting, and a heterogeneous fleet, as well as for the loading optimization subproblem, e.g., stackability, fragility, and LIFO unloading. A proven loading optimization tool from WITRON and an algorithm developed by the chair are used to solve the packing problem.
In order to achieve acceptable solutions of good quality, the route planning and the packing problem must be solved in an integrated way. The difficulty of the task lies in the combination of these two demanding planning problems. As an additional challenge, numerous practical restrictions must be taken into account.
To solve the problem, classical construction and improvement heuristics are implemented. In integrated planning, the frequent calls to the loading optimization tool represent the bottleneck in terms of computing time. In order to keep these calls as low as possible, an innovative Pack-First Route-Second approach is pursued. The basic idea here is to approximate the time-consuming, three-dimensional problem by a one-dimensional quantity, the loading meters, and thus to save computing time. In addition, a modern metaheuristic is implemented.
Basic principle of the Pack-First Route-Second approach by Bortfeldt / Homberger (2013): overestimation of the real load meters of different load carrier groups and so-called customer combinations.
WITRON Logistik + Informatik GmbH is one of the market leaders worldwide in the planning and implementation of highly dynamic storage and order picking systems in intralogistics. WITRON was founded in 1971 and now employs more than 5000 people worldwide.
Involved Persons
Dipl.-Wi.-Ing. Leopold Kuttner
Felix Tamke, M.Sc.
Dipl.-Wi.-Ing. Florian Linß
Prof. Dr. Udo Buscher