Roll-On-Roll-Off/Skip Vehicle Routing Problems with Multiple Sequentially Dependant and Mutually Exclusive order-Activities

Specialeforsvar Gustav Heerfordt Bay

Titel: Roll-On-Roll-Off/Skip Vehicle Routing Problems with  Multiple Sequentially Dependant and Mutually Exclusive Order-Activities

Abstract: In recent years increases in waste recycling have caused an increase in the need for transportation of large quantities of waste sorted in very large containers known as Roll-On-Roll-Off / Skip (RoRo) containers and vehicles to handle these. The RoRo routing problem adds a new level of complexity due to the added handling of these large containers and the waste they contain.
In this thesis we address the RoRo routing problem which is a vehicle routing problem with time windows, capacity constraints and with multiple sequentially dependant and mutually exclusive order-activities. When it comes to RoRo problems, not much research have been done to find exact solutions in the past, most research on the RoRo problem has been on finding good heuristics to solve the problem rather than exact solutions. This thesis seeks to amend this.
In this thesis, the RoRo routing problem is formulated as a MIP. In order to ease the solution of the problem via commercial solvers, warm-starting heuristics are proposed as well as valid inequalities and reformulations.
Tests performed on randomly generated instances based on a real case data show that the proposed approach improves significantly the performance of commercial solvers.
This paper also serves as a manuscript for further improvements of the RoRo problem as one could improve on this research by decomposition.

Vejleder: Giovanni Pantuso
Censor:    Niklas Kohl, CBS