GWO (Mirjalili et al., 2014) is a relatively new population based stochastic algorithm that has received considerable attention in recent literature, based on the hunting habits and hierarchy that exists in a pack of grey wolves (Canis lupus). The wolves are divided as alpha, beta, delta and omega wolves to simulate the hierarchy in a pack, with the alpha being the fittest wolf or population member. In this algorithm, the optimal solution is considered as “prey” and the exploration and exploitation of the search space is done through specially designed “Searching for prey” and “Attacking prey” stages respectively.