Stefan Minner

The value of stochastic crowd resources and strategic location of mini-depots for last-mile delivery: A Benders decomposition approach

  • Pirmin Fontaine
  • Stefan Minner
  • Santiago Nieto-Isaza
    • Categories Applications - OR and Management Sciences, Supply Chain Management, Transportation Tags , , ,

    Crowd-shipping is an emergent solution to avoid the negative effects caused by the growing demand for last-mile delivery services. Previous research has studied crowd-shipping typically at an operational planning level. However, the study of support infrastructure within a city logistics framework has been neglected, especially from a strategic perspective. We investigate a crowd-sourced last-mile parcel … Read more

    A Branch-and-Price Algorithm for the Vehicle Routing Problem with Stochastic Demands and Probabilistic Duration Constraints

  • Alexandre M. Florio
  • Juan-José Salazar-González
  • Richard F. Hartl
  • Stefan Minner
    • Categories Applications - OR and Management Sciences

    In many routing applications, it is necessary to place limits on the duration of the individual routes. When demands are stochastic and restocking during route execution is allowed, the durations of the resulting routes are also stochastic. In this paper, we consider the vehicle routing problem with stochastic demands and (probabilistic) duration constraints (VRPSD-DC). We … Read more

    Simulation Optimization for the Stochastic Economic Lot Scheduling Problem with Sequence-Dependent Setup Times

  • Nils Löhndorf
  • Stefan Minner
  • Manuel Riel
    • Categories Optimization of Simulated Systems, Scheduling, Stochastic Approaches Tags , , , , ,

    We consider the stochastic economic lot scheduling problem (SELSP) with lost sales and random demand, where switching between products is subject to sequence-dependent setup times. We propose a solution based on simulation optimization using an iterative two-step procedure which combines global policy search with local search heuristics for the traveling salesman sequencing subproblem. To optimize … Read more

    Optimizing Trading Decisions for Hydro Storage Systems using Approximate Dual Dynamic Programming

  • Nils Löhndorf
  • David Wozabal
  • Stefan Minner
    • Categories Applications - OR and Management Sciences, Dynamic Programming, Stochastic Programming Tags , , ,

    We propose a new approach to optimize operations of hydro storage systems with multiple connected reservoirs which participate in wholesale electricity markets. Our formulation integrates short-term intraday with long-term interday decisions. The intraday problem considers bidding decisions as well as storage operation during the day and is formulated as a stochastic program. The interday problem … Read more

    Simulation Optimization for the Stochastic Economic Lot Scheduling Problem

  • Nils Löhndorf
  • Stefan Minner
    • Categories Dynamic Programming, Optimization of Simulated Systems, Scheduling Tags , , , , ,

    We study simulation optimization methods for the stochastic economic lot scheduling problem. In contrast to prior research, we focus on methods that treat this problem as a black box. Based on a large-scale numerical study, we compare approximate dynamic programming with a global search for parameters of simple control policies. We propose two value function … Read more