The Online Shortest Path Problem: Learning Travel Times Using A Multi-Armed Bandit Framework

In the age of e-commerce, many logistic companies must operate in large road networks without accurate knowledge of travel times for their specific fleet of vehicles. Moreover, millions of dollars are spent on routing services that do not accurately capture the specific characteristics of the companies’ drivers and the types of vehicles they must use. … Read more

Scenario Consensus Algorithms for Solving Stochastic and Dynamic Problems

In transportation problems and in many other planning problems, there are important sources of uncertainty that must be addressed to find effective and efficient solutions. A common approach for solving these dynamic and stochastic problems is the Multiple Scenario Approach (MSA), that has been proved effective for transportation problems, but it does not provide flexibility … Read more

Dynamic Discretization Discovery for Solving the Continuous Time Inventory Routing Problem with Out-and-Back Routes

In time dependent models, the objective is to find the optimal times (continuous) at which activities occur and resources are utilized. These models arise whenever a schedule of activities needs to be constructed. A common approach consists of discretizing the planning time and then restricting the decisions to those time points. However, this approach leads … Read more

The Continuous Time Inventory Routing Problem

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

Branch-and-Price for Routing with Probabilistic Customers

The Vehicle Routing Problem with Probabilistic Customers (VRP-PC) is a fundamental building block within the broad family of stochastic routing models, and has two decision stages. In the first stage, a dispatcher determines a set of vehicle routes serving all potential customer locations, before actual requests for service realize. In the second stage, vehicles are … Read more