Ingeniare. Revista chilena de ingeniería
versión On-line ISSN 0718-3305
ORTEGA, Pablo; OLIVA, Cristian; FERLAND, Jacques y CEPEDA, Manuel. MULTIPLE ANT COLONY SYSTEM FOR A VRP WITH TIME WINDOWS AND SCHEDULED LOADING. Ingeniare. Rev. chil. ing. [online]. 2009, vol.17, n.3, pp. 393-403. ISSN 0718-3305. doi: 10.4067/S0718-33052009000300013.
The vehicle routing problem with time windows and scheduled loading [VRPTWSL] requires not only the design of routes with time windows and capacity constraints, but also a schedule of the departures of vehicles from the depot given a load time due to the limited resources available to load the demand in the vehicles. A mathematical formulation of the vehicle routing problem with time windows and scheduled loading is presented and a metaheuristics based on Multiple Ant Colony System is proposed and implemented where two ant colonies, each with a single objective function, are organized in a hierarchical way. A time update procedure is incorporated into the ant constructive procedure to update and schedule the departure of a vehicle from the depot when each ant moves to a new customer-node. Constraint programming is used to determine a feasible move to a new customer-node. As [VRPTWSL] incorporates the vehicle departure scheduling, the algorithm presented in this paper has a direct application to real problems, in this way [VRPTWSL] can be taken as an important advance for practical vehicle routing problems.
Palabras clave : Vehicle routing problem; ant colony system; scheduling.