An Auto-carrier Loading Problem with Inter-set Costs in Urban Outbound Logistics of Automobiles

This paper studies a loading problem arising in the urban outbound logistics of automobiles. The problem is to assign a given set of orders of finished cars to a given set of heterogeneous auto-carriers such that the cars can be loaded and delivered from a depot to multiple destinations. A value is given to each order to represent its urgency level, and an interset cost is defined among the destinations to estimate the transportation cost. The objective is to maximize the weighted total value of the assigned orders minus the total inter-set cost subject to a full-load constraint and a special loading structure. An integer programming model and a column generation based heuristic algorithm are proposed. In addition, parallel programing is tested in the computational experiments. Computational results show that our algorithm can generate near-optimality solutions for practically-sized problems efficiently, and outperforms the integer programing model and a rule-based method applied in practice.