Middle Mile Consolidation Network Design with Fixed Origins and Destinations: Time-Constrained Rate-Based Models

Many large e-commerce retailers now have the scale to operate their own middle mile consolidation networks, moving customer shipments from stocking locations to last mile delivery partners using a private set of freight transportation loads that reduce outbound logistics cost. In this article, we study a middle mile network design problem with fixed origins and … Read more

Service Network Design for Same-Day Delivery with Hub Capacity Constraints

We study a new service network design problem for an urban same-day delivery system in which the number of vehicles that can simultaneously load or unload at a hub is limited. Due to the presence of both time constraints for the commodities and capacity constraints at the hubs, it is no longer guaranteed that a … Read more

Optimizing Package Express Operations in China

We explore optimization models to support the planning and operations functions at package express carriers in China. The models simultaneously consider ground and air transportation, company-owned and purchased capacity, multiple service products, and shipments becoming available throughout the day. An extensive computational study using real-life data shows the efficacy of the models, provides insights into … Read more

The Continuous Time Service Network Design Problem

Consolidation carriers transport shipments that are small relative to trailer capacity. To be cost-effective, the carrier must consolidate shipments, which requires coordinating their paths in both space and time, i.e., the carrier must solve a Service Network Design problem. Most service network design models rely on discretization of time, i.e., instead of determining the exact … Read more