An Ant Colony System for the Skilled, Multi-depot VRP with Due Dates and Time Windows

This article introduces a real-world maintenance scheduling problem that can be defined as a Skilled Multi-Depot Vehicle Routing Problem with Due Dates and Time Windows, or Skill-MDVRPDDTW, and addresses two methods to solve it. One is a greedy heuristic inspired from the real-world planning processes used in a water service management context, and the other is a version of the Ant Colony System algorithm, widely used in the literature for the Vehicle Routing Problem and its variants and adapted to fit the features of the real-world maintenance problem. Both the problem and the algorithms are positioned in the literature and mathematically formulated, then experiments and results are discussed and compared through a set of various indicators.