A Less-Than-Truckload Single Freight Carrier Collaboration Planning Problem under Dynamic Capacities

摘要

This paper addresses the deterministic dynamic single carrier collaboration problem (DDSCCP)for the small- to medium-sized less-than-truckload (LTL) industry. In the DDSCCP, addressedfrom a dynamic planning perspective, a carrier of interest seeks to collaborate with other carriersby acquiring collaborative capacity while minimizing its costs related to servicing excessdemand and shipment delays (holding costs). In contrast to conventional dynamic networkproblems that typically view demand as dynamic, in the proposed LTL carrier-carriercollaboration framework, capacities are dynamic but known a priori, and demand is fixed butconstrained by latest entry and earliest exit time windows. The DDSCCP is formulated as abinary (0-1) multi-commodity minimum cost flow problem and solved using a branch-and-cutalgorithm. Its inherent network structure is exploited to generate the lower bounds to the branch-and-cut algorithm using the network simplex method. Lower bounds are also generated for thebranch-and-cut algorithm by relaxing the integrality constraints. The computational performanceof these two approaches is compared using numerical experiments. Numerical experiments arealso conducted to seek insights on the computational performance under various network sizesand number of shipments. The impact of holding costs is explored by using a collaborativediscount rate on the acquired capacity to represent the degree of collaboration. The collaborativestrategies are compared to a non-collaborative short-term leasing strategy. The results indicateinherent trade-offs at the higher degrees of collaboration between waiting for more affordablecollaborative capacity and incurring higher holding costs. They also suggest that collaboratingcarriers experience increased capacity utilization.