Who Has Access to E-Commerce and When? Time-Varying Service Regions in Same-Day Delivery

Motivated by access and equity issues in e-commerce, we study the design of same-day delivery (SDD) systems under the assumption that service regions are allowed to vary over the course of the day; equivalently, that customers in different locations may have access to SDD for different lengths of time over the service day or may … Read more

A Prescriptive Machine Learning Method for Courier Scheduling on Crowdsourced Delivery Platforms

Crowdsourced delivery platforms face the unique challenge of meeting dynamic customer demand using couriers not employed by the platform. As a result, the delivery capacity of the platform is uncertain. To reduce the uncertainty, the platform can offer a reward to couriers that agree to be available to make deliveries for a specified period of … Read more

Fleet Sizing and Service Region Partitioning for Same-Day Delivery Systems

We study the linked tactical design problems of fleet sizing and partitioning a service region into vehicle routing zones for same-day delivery (SDD) systems. Existing SDD studies focus primarily on operational dispatch problems and do not consider system design questions. Prior work on SDD system design has not considered the fleet sizing decision when a … 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

Order Acceptance in Same-Day Delivery

We study order acceptance dynamics in same-day delivery systems by formulating the Dynamic Dispatch Waves Problem with Immediate Acceptance, which models integrated request management and order distribution for dynamically arriving requests. When a delivery request arrives, a decision is made immediately to accept (offer service) or reject (with a penalty). Accepted requests are not available … Read more

Tactical Design of Same-Day Delivery Systems

We study tactical models for the design of same-day delivery (SDD) systems. Same-day fulfillment in e-commerce has seen substantial growth in recent years, and the underlying management of such services is complex. While the literature includes operational models to study SDD, they tend to be detailed, complex, and computationally difficult to solve, and thus may … Read more

Crowdshipping and Same-day Delivery: Employing In-store Customers to Deliver Online Orders

Same-day delivery of online orders is becoming an indispensable service for large retailers. We explore an environment in which in-store customers supplement company drivers and can take on the task of delivering online orders on their way home. Because online orders as well as in-store customers willing to make deliveries arrive throughout the day, it … Read more

The Dynamic Dispatch Waves Problem for Same-Day Delivery

We study same-day delivery systems by formulating the Dynamic Dispatch Waves Problem (DDWP), which models a distribution center where geographically located delivery orders realize dynamically throughout the day. At each decision epoch (wave), the system’s operator chooses whether or not to dispatch a vehicle route loaded with orders ready for service, to minimize vehicle travel … Read more

City Logistics: Challenges and Opportunities

Today, around 54% of the world’s population lives in urban areas. By 2050, this share is expected to go up significantly. As a result, city logistics, which focuses on the efficient and effective transportation of goods in urban areas while taking into account the negative effects on congestion, safety, and environment, is critical to ensuring … Read more

The One-Dimensional Dynamic Dispatch Waves Problem

We study same-day delivery (SDD) distribution systems by formulating the Dynamic Dispatch Wave Problem (DDWP), which models a depot where delivery requests arrive dynamically throughout a service day. At any dispatch epoch (wave), the information available to the decision maker is (1) a set of known, open requests which remain unfulfilled, and (2) a set … Read more