Vehicle re-routing under disruption in cross-dock network with time constraints

This study expands on the investigation of the vehicle routing problem with cross-dock (VRPCD) by incorporating disruption in a network with suppliers, customers, and a single cross-dock. It is assumed that the disruption (e.g., traffic accident or mechanical failure) impacts the scheduled pickup times of vehicles carrying freight; hence, pickup or delivery is affected by late vehicle arrivals to suppliers, cross-docks, and customers as well as increased transportation cost for the carrier. To help decision makers mitigate the impact of this type of disruption, mixed-integer linear programs (MILPs) are developed to model VRPCD with time-window constraints under both normal and disrupted conditions that will quantify the impact of disruption. The Golden Ball metaheuristic is adapted to provide an optimal or near-optimal solution of the MILPs in a short time period. To demonstrate the effectiveness of the proposed models and algorithms, numerical experiments are performed on hypothetical networks containing a realistic number of pickup and delivery locations. Results from numerical experiments and ANOVA analysis showed that: 1) the cross-dock is able to cope with the disruption when the number of disrupted nodes is small, 2) early breakdown of an inbound vehicle with fewer nodes on its routes causes smaller service delays, 3) as the number of disrupted nodes increases, it is advantageous to reroute outbound vehicles, and 4) when the breakdown occurs earlier in the planning horizon, it is better to reroute both inbound and outbound vehicles whereas only outbound vehicles should be rerouted when the breakdown happens later in the day.