In general PSO can be used to find the optimal solution among users having a population size lets say 20.

But how can the PSO can be implemented to find the optimal solution if users are getting grouped into clusters.In this case each group contains one or more clusters containing different number of users.Therefore if I am not mistaken , finding the optimal solution deals with finding the best group of clusters containing users.If it is so then how it can be done.If I am wrong please provide me the correct way of finding the optimal solution.