Martin Savelsbergh We introduce the Meal Delivery Routing Problem (MDRP) to formalize and study an important emerging class of dynamic delivery operations. We develop optimization-based algorithms tailored to solve the courier assignment (dynamic vehicle routing) and capacity management (offline shift scheduling) problems encountered in meal delivery operations. Extensive computational experiments using instances with realistic size, geography, urgency … Read more
We consider a continuous time variant of the Inventory Routing Problem in which the maximum quantity that can delivered at a customer depends on the customer’s storage capacity and product inventory at the time of the delivery. We investigate critical components of a dynamic discretization discovery algorithm and demonstrate in an extensive computational study that … Read more
Cities are drivers of economic development, providing infrastructure to support countless activities and services. Today, the world’s 750 biggest cities account for more than 57% of the global GDP and this number is expected to increase to 61% by 2030. More than half of the world’s population lives in cities, or urban areas, and this … Read more
Despite recent interest in multiobjective integer programming, few algorithms exist for solving biobjective mixed integer programs. We present such an algorithm: the Boxed Line Method. For one of its variants, we prove that the number of single-objective integer programs solved is bounded by a linear function of the number of nondominated line segments in the … Read more
Unmanned Aerial Vehicles (UAVs), commonly referred to as drones, have recently seen an increased level of interest as their potential use in same-day home delivery has been promoted and advocated by large retailers and courier delivery companies. We introduce a novel way to exploit drones in same-day home delivery settings: drone resupply. We consider a … Read more
To deliver to consumers in densely populated urban areas, companies often employ a two-echelon logistics system. In a two-echelon logistics system, the entry point for goods to be delivered in the urban area is a city distribution center (CDC). From a CDC the goods are transported to an intermediate facility, from where the goods are … Read more
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
We study the vehicle routing problem with roaming delivery locations in which the goal is to find a least-cost set of delivery routes for a fleet of capacitated vehicles and in which a customer order has to be delivered to the trunk of the customer’s car during the time that the car is parked at … Read more
We study conditions under which the objective functions of a multi-objective 0-1 integer linear program guarantee the existence of an ideal point, meaning the existence of a feasible solution that simultaneously minimizes all objectives. In addition, we study the complexity of recognizing whether a set of objective functions satisfies these conditions: we show that it … Read more
The desire of companies to offer same-day delivery leads to interesting new routing problems. We study the complexity of a setting in which a delivery to a customer is guaranteed to take place within a pre-specified time after the customer places the order. Thus, an order has a release date (when the order is placed) … Read more