Scheduling

The Multiple Part Type Cyclic Flow Shop Robotic Cell Scheduling Problem: A Novel and Comprehensive Mixed Integer Linear Programming Approach

  • Atabak Elmi
  • Asef Nazari
  • Dhananjay Thiruvady
    • Categories (Mixed) Integer Nonlinear Programming, Scheduling, Transportation

    This paper considers the problem of cyclic ow shop robotic cell scheduling deploying several single and dual gripper robots. In this problem, dierent part types are successively processed on multiple machines with dierent pickup criteria including free pickup, pickup within time-windows and no-waiting times. The parts are transported between the machines by the robots. We … Read more

    Automated timetabling for small colleges and high schools using huge integer programs

  • Joshua S. Friedman
    • Categories Scheduling Tags , ,

    We formulate an integer program to solve a highly constrained academic timetabling problem at the United States Merchant Marine Academy. The IP instance that results from our real case study has approximately both 170,000 rows and columns and solves to near optimality in 12 hours, using a commercial solver. Our model is applicable to both … Read more

    Flow formulations for curriculum-based course timetabling

  • Niels-Christian F. Bagger
  • Thomas R. Stidsen
  • Simon Kristiansen
  • Matias Sørensen
    • Categories (Mixed) Integer Linear Programming, Network Optimization, Scheduling Tags , , ,

    In this paper we present two mixed-integer programming formulations for the curriculum based course timetabling problem (CTT). We show that the formulations contain underlying network structures by dividing the CTT into two separate models and then connect the two models using flow formulation techniques. The first mixed-integer programming formulation is based on an underlying minimum … Read more

    New Constraints and Features for the University Course Timetabling Problem

  • Sam Applebee
  • Paul Alexandru Bucur
  • Philipp Hungerländer
  • Markus Aschinger
  • Harry Edmonds
  • Kerstin Maier
    • Categories 0-1 Programming, Scheduling

    The university course timetabling problem deals with the task of scheduling lectures of a set of university courses into a given number of rooms and time periods, taking into account various hard and soft constraints. The goal of the International Timetabling Competitions ITC2002 and ITC2007 was to establish models for comparison that cover the most … Read more

    Variants in Modeling Time Aspects for the Multiple Traveling Salesmen Problem with Moving Targets

  • Armin Fügenschuh
  • Anke Stieber
    • Categories (Mixed) Integer Linear Programming, Branch and Cut Algorithms, Scheduling Tags , , , ,

    The multiple traveling salesmen problem with moving targets (MT-SPMT) is a generalization of the classical traveling salesmen problem (TSP), where the targets (cities or objects) are moving over time. Additionally, for each target a visibility time window is given. The task is to find routes for several salesmen so that each target is reached exactly … Read more

    Mixed-integer Programming Based Approaches for the Movement Planner Problem: Model, Heuristics and Decomposition

  • Chiwei Yan
  • Luyi Yang
    • Categories Scheduling, Transportation Tags , , , ,

    This is the first prize winning report for the 2012 INFORMS Railway Application Section Problem Solving Competition (https://www.informs.org/Community/RAS/Problem-Solving-Competition/2012-RAS-Problem-Solving-Competition). Article Download View Mixed-integer Programming Based Approaches for the Movement Planner Problem: Model, Heuristics and Decomposition

    Resource-constrained scheduling with non-constant capacity and non-regular activities

  • Giorgio Fasano
    • Categories (Mixed) Integer Linear Programming, Applications - Science and Engineering, Scheduling Tags , , , , , , ,

    This work is inspired by very challenging issues arising in space logistics. The problem of scheduling a number of activities, in a given time elapse, optimizing the resource exploitation is discussed. The available resources are not constant, as well as the request, relative to each job. The mathematical aspects are illustrated, providing a time-indexed MILP … Read more

    On the NP-Completeness of the Multi-Period Minimum Spanning Tree Problem

  • Rosklin Chagas
  • Alexandre Cunha
    • Categories Combinatorial Optimization, Scheduling, Telecommunications Tags ,

    In this note, we consider the Multi-period Minimum Spanning Tree Problem (MMST), a variant of the well known Minimum Spanning Tree Problem (MST), that consists in the fol- lowing. Given a connected and undirected graph G and a finite discrete time horizon, one has to schedule the moment in time edges are added to a … Read more

    A Two-Stage Stochastic Program for Multi-shift, Multi-analyst, Workforce Optimization with Multiple On Call Options

  • Douglas S. Altner
  • Anthony C. Rojas
  • Leslie D. Servi
    • Categories Scheduling, Stochastic Programming

    Motivated by a cybersecurity workforce optimization problem, this paper investigates optimizing staffing and shift scheduling decisions given unknown demand and multiple on call staffing options at a 24/7 firm with three shifts per day, three analyst types, and several staffing and scheduling constraints. We model this problem as a two-stage stochastic program and solve it … Read more

    Steiner tree network scheduling with opportunity cost of time

  • Fabien Cornillier
    • Categories Facility Planning and Design, Network Optimization, Scheduling Tags , ,

    This paper points out the impact of opportunity cost of time (high discount rate or high rate of time preference, time-dependent profits, etc.) in designing real-world Steiner trees like electricity, gas, water, or telecommunications networks. We present the Steiner Tree Scheduling Problem which consists of finding a Steiner tree in an activity-on-arc graph that spans … Read more