Swarm Intelligence in Solving Stochastic Capacitated Vehicle Routing Problem

In this paper, the two most popular Swarm Intelligence approaches (Particle Swarm Optimization and Ant Colony Optimization) are compared in the task of solving the Capacitated Vehicle Routing Problem with Traffic Jams (CVRPwTJ). The CVRPwTJ is a highly challenging optimization problem for the following reasons: while the CVRP is already a problem of NP complexity, adding another stochastic layer to its definition (related to stochastic occurrence of traffic jams while traversing the planned vehicle routes) further increases the problem's difficulty by requiring that potential solution methods be capable of on-line adaptation of the routes, in response to changing traffic conditions. The results presented in the paper shed light on the underlying differences between ACO and PSO in terms of their suitability to solving particular instances of CVRPwTJ.