vehicle routing

Hardness of pricing routes for two-stage stochastic vehicle routing problems with scenarios

  • Matheus Jun Ota
  • Ricardo Fukasawa
    • Categories Combinatorial Optimization, Integer Programming, Stochastic Programming Tags , ,

    The vehicle routing problem with stochastic demands (VRPSD) generalizes the classic vehicle routing problem by considering customer demands as random variables. Similarly to other vehicle routing variants, state-of-the-art algorithms for the VRPSD are often based on set-partitioning formulations, which require efficient routines for the associated pricing problems. However, all these set-partitioning-based approaches have strong assumptions … Read more

    The Robust Bike Sharing Rebalancing Problem: Formulations and a Branch-and-Cut Algorithm

  • Bruno Petrato Bruck
  • Walton P. Coutinho
  • Pedro Munari
    • Categories Branch and Cut Algorithms, Robust Optimization, Transportation Tags , , ,

    Bike Sharing Systems (BSSs) offer a sustainable and efficient urban transportation solution, bringing flexible and eco-friendly alternatives to city logistics. During their operation, BSSs may suffer from unbalanced bike distribution among stations, requiring rebalancing operations throughout the system. The inherent uncertain demand at the stations further complicates these rebalancing operations, even when performed during downtime. … Read more

    The Vehicle Routing Problem with Access Restrictions

  • Munise Kubra Sahin
    • Categories Applications - OR and Management Sciences, Production and Logistics, Transportation Tags , , , ,

    To mitigate the negative effect of freight vehicles on urban areas, many cities have implemented road accessibility restrictions, including limited traffic zones, which restrict access to specific areas during certain times of the day. Implementing these zones creates a trade-off between the delivery cost and time, even under the assumption of equal traversal time and … Read more

    Fair stochastic vehicle routing with partial deliveries

  • Natasja Sluijk
  • Walter Rei
  • Joris Kinable
  • Michel Gendreau
  • Tom Van Woensel
    • Categories Branch and Cut Algorithms, Stochastic Programming, Transportation Tags , , ,

    A common assumption in the models for the vehicle routing problem with stochastic demands is that all demands must be satisfied. This is achieved by including recourse actions in two-stage stochastic programming formulations or by ensuring with a high probability that all demand fits within the vehicle capacity (chance-constrained formulations). In this work, we relax … Read more

    Column Elimination for Capacitated Vehicle Routing Problems

  • Anthony Karahalios
  • Willem-Jan van Hoeve
    • Categories (Mixed) Integer Linear Programming, Branch and Cut Algorithms, Dynamic Programming Tags , , ,

    We introduce a column elimination procedure for the capacitated vehicle routing problem. Our procedure maintains a decision diagram to represent a relaxation of the set of feasible routes, over which we define a constrained network flow. The optimal solution corresponds to a collection of paths in the decision diagram and yields a dual bound. The … Read more

    A Column Generation Approach for the Lexicographic Optimization of Intra-Hospital Transports

  • Andreas Bärmann
  • Alexander Martin
  • Alexander Müller
  • Dieter Weninger
    • Categories Integer Programming, Multi-Criteria Optimization, Transportation Tags , , , , ,

    Over the last fewyears, the efficient design of processes in hospitals and medical facilities has received more and more attention, particularly when the improvement of the processes is aimed at relieving theworkload of medical staff. To this end,we have developed a method to determine optimal allocations of intra-hospital transports to hospital transport employees. When optimizing … Read more

    Insertion Heuristics for a Class of Dynamic Vehicle Routing Problems

  • Adam N. Letchford
    • Categories Combinatorial Optimization, Transportation Tags ,

    We consider a simple family of dynamic vehicle routing problems, in which we have a fixed fleet of identical vehicles, and customer requests arrive during the route-planning process. For this kind of problem, it is natural to use an insertion heuristic. We test several such heuristics computationally, on two different variants of the problem. It … Read more

    The complexity of branch-and-price algorithms for the capacitated vehicle routing problem with stochastic demands

  • Ricardo Fukasawa
    • Categories Combinatorial Optimization, Integer Programming, Stochastic Programming Tags , ,

    The capacitated vehicle routing problem with stochastic demands (CVRPSD) is a variant of the deterministic capacitated vehicle routing problem where customer demands are random variables. While the most successful formulations for several deterministic vehicle-routing problem variants are based on a set-partitioning formulation, adapting such formulations for the CVRPSD under mild assumptions on the demands remains … Read more

    Routing and resource allocation in non-profit settings with equity and efficiency measures under demand uncertainty

  • Faisal Alkaabneh
  • Karmel S. Shehadeh
  • Ali Diabat
    • Categories (Mixed) Integer Linear Programming, Stochastic Programming Tags , , , ,

    Motivated by food distribution operations for non-profit organizations, we study a variant of the stochastic routing-allocation problem under demand uncertainty, in which one decides the assignment of trucks for demand nodes, the sequence of demand nodes to visit (i.e., truck route), and the allocation of food supply to each demand node. We propose three stochastic … Read more

    Minimizing earliness-tardiness costs in supplier networks – A Just-in-time Truck Routing Problem

  • Julian Baals
  • Simon Emde
  • Turkensteen Marcel
    • Categories Meta Heuristics, Production and Logistics Tags , , , ,

    We consider a routing problem where orders are transported just-in-time from several suppliers to an original equipment manufacturer (OEM). This implies that shipments cannot be picked up before their release date when they are ready at the supplier and should be delivered as close as possible to their due date to the OEM. Every shipment … Read more