Parallel simulated annealing for the delivery problem

A delivery problem which reduces to an NP-complete set-partitioning problem is considered. Two algorithms of parallel simulated annealing, i.e. the simultaneous independent searches and the simultaneous periodically interacting searches are investigated. The objective is to improve the accuracy of solutions to the problem by applying parallelism. The accuracy of a solution is meant as its proximity to the optimum solution. The empirical evidence supported by the statistical analysis indicates that the interaction of processes in parallel simulated annealing can yield more accurate solutions to the delivery problem as compared to the case when the processes run independently.