We introduce an interesting and challenging routing and scheduling problem arising in the city operations of SF Express, a large package express carrier in China. Vehicles execute multiple trips during a planning horizon spanning multiple shifts, where a trip can involve deliveries only, pickups only, or deliveries followed by pickups. Complicating factors include split deliveries and pickups, cross-trip consistency requirements, and limited unloading capacity at the main hubs. We develop an optimization-based multi-phase heuristic solution approach seeking to minimize the number of vehicles used. An extensive computational study using real-world instances demonstrates the effectiveness of the approach.
H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, October, 2020