CompetAnts for problem solving

In this paper we propose a multi-colony Ant System where the colonies solve a multi-criteria optimization problem concerned with goods transportation. The criteria are minimization of the required fleet sizes and minimization of total travel times. However, as both criteria can be quantified in terms of money we use a weighted single objective function. The colonies differ from each other by the heuristic information which guides their solution construction process. Information exchange occurs as ants from one population observe the pheromone trails of other populations and decide whether or not to utilize this information. Furthermore, population sizes are adapted according to the relative fitness of the populations. The results show the advantages of this approach over common Ant System approaches.