network design

Consolidation in Crowdshipping with Scheduled Transfer Lines: A Surrogate-Based Network Design Framework

  • Ramazan Çevik
  • Ali Şardağ
  • Barış Yıldız
    • Categories Combinatorial Optimization, Optimization in Data Science, Transportation Tags , , ,

    Abstract: Crowdshipping has gained attention as an emerging delivery model thanks to advantages such as flexibility and an asset-light structure. Yet, it chronically suffers from a lackof mechanisms to create and exploit consolidation opportunities, limiting its efficiency and scalability. This work contributes to the literature in two ways: first, by introducing a novel consolidation concept … Read more

    Paving the Way for More Accessible Cancer Care in Low-Income Countries with Optimization

  • Abel Sapirstein
  • Lauren Steimle
  • Mathieu Dahan
    • Categories Applications - OR and Management Sciences Tags , , , , ,

    Cancers are a growing cause of morbidity and mortality in low-income countries. Geographic access plays a key role in both timely diagnosis and successful treatment. In areas lacking well-developed road networks, seasonal weather events can lengthen already long travel times to access care. Expanding facilities to offer cancer care is expensive and requires staffing by … Read more

    Fair network design problem: an application to EV charging station capacity expansion

  • Nagisa Sugishita
  • Margarida Carvalho
    • Categories Bilevel Optimization Tags , , ,

    This study addresses the bilevel network design problem (NDP) with congestion. The upper-level decision-maker (a network designer) selects a set of arcs to add to an existing transportation network, while the lower-level decision-makers (drivers) respond by choosing routes that minimize their individual travel times, resulting in user equilibrium. In this work, we propose two novel … Read more

    Strengthening Dual Bounds for Multicommodity Capacitated Network Design with Unsplittable Flow Constraints

  • Lacy M. Greening
  • Santanu S. Dey
  • Alan L. Erera
    • Categories Integer Programming, Network Optimization, Production and Logistics Tags , , ,

    Multicommodity capacitated network design (MCND) models can be used to optimize the consolidation of shipments within e-commerce fulfillment networks. In practice, fulfillment networks require that shipments with the same origin and destination follow the same transfer path. This unsplittable flow requirement complicates the MCND problem, requiring integer programming (IP) formulations with binary variables replacing continuous … Read more

    A Branch-and-Price-and-Cut Algorithm for Discrete Network Design Problems Under Traffic Equilibrium

  • David
  • Michael Levin
    • Categories (Mixed) Integer Nonlinear Programming, Bilevel Optimization, Transportation Tags , , , ,

    This study addresses discrete network design problems under traffic equilibrium conditions or DNDPs. Given a network and a budget, DNDPs aim to model all-or-nothing decisions such as link addition to minimize network congestion effects. Congestion is measured using traffic equilibrium theory where link travel times are modeled as convex flow-dependent functions and where users make … Read more

    A Stochastic Benders Decomposition Scheme for Large-Scale Stochastic Network Design

  • Dimitris Bertsimas
  • Ryan Cory-Wright
  • Jean Pauphilet
  • Periklis Petridis
    • Categories Cutting Plane Approaches, Network Optimization, Stochastic Programming Tags , ,

    Network design problems involve constructing edges in a transportation or supply chain network to minimize construction and daily operational costs. We study a stochastic version where operational costs are uncertain due to fluctuating demand and estimated as a sample average from historical data. This problem is computationally challenging, and instances with as few as  100 … Read more

    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

    Benders decomposition for Network Design Covering Problems

  • Victor Bucarey
  • Bernard Fortz
  • Martine Labbé
  • Juan A. Mesa
  • Natividad González-Blanco
    • Categories Facility Planning and Design, Transportation Tags , , ,

    We consider two covering variants of the network design problem. We are given a set of origin/destination(O/D) pairs and each such O/D pair is covered if there exists a path in the network from the origin to the destination whose length is not larger than a given threshold. In the first problem, called the maximal … Read more

    The Multi-Stop Station Location Problem

  • Miriam Ganz
  • Erik Mühmer
  • Felix J. L. Willamowski
    • Categories Approximation Algorithms, Network Optimization, Transportation Tags , , , ,

    We introduce the (directed) multi-stop station location problem. The goal is to install stations such that ordered (multi-)sets of stops can be traversed with respect to range restrictions that are reset whenever a station is visited. Applications arise in telecommunications and transportation, e.g., charging station placement problems. The problem generalizes several network optimization problems such … Read more

    Evaluating on-demand warehousing via dynamic facility location models

  • Kaan Unnu
  • Jennifer Pazour
    • Categories (Mixed) Integer Linear Programming, Supply Chain Management, Transportation Tags , , , , , ,

    On-demand warehousing platforms match companies with underutilized warehouse and distribution capabilities with customers who need extra space or distribution services. These new business models have unique advantages, in terms of reduced capacity and commitment granularity, but also have different cost structures compared to traditional ways of obtaining distribution capabilities. This research is the first quantitative … Read more