Scheduling with latest arrival consolidation in service network design problems

Yiğit, Aybeniz
In this thesis, we consider the service network design problem of a ground transportation based delivery system, in which routes of demands of commodities between any origin-destination pair are determined. A commodity can be sent from its origin to its destination through direct delivery, however such a routing would not effectively make use of the vehicles used for transportation. To benefit from economies of scale, a networking policy based on consolidation is generally applied in service networks. We consider freight-consolidation, in which different commodities are consolidated to be transported using common vehicles and consolidation operations are performed at stations, some of which are chosen as terminals. Nonsimultaneous arrival of commodities necessitates waiting times at stations/terminals. The latest arrival consolidation in service network design problem is then, a minimax model that considers the delays at terminals and focuses on minimization of the arrival time of the last arrived commodity to its destination. For the solution of the model, we present exact and heuristic solution procedures. We develop a tailored Generalized Benders Decomposition algorithm and to address larger size networks, we develop a Large Neighborhood Search based algorithm. We show the effectiveness of the heuristic solution procedure by performing extensive computational experiments. In the constructed service network, each direct ride between stations is assumed to be performed by the same vehicle. Extending this assumption to allow multiple vehicles and using event-activity-network representation, we develop a delay management model for service networks that apply latest arrival consolidation.
Citation Formats
A. Yiğit, “Scheduling with latest arrival consolidation in service network design problems,” Ph.D. - Doctoral Program, Middle East Technical University, 2014.