The proposed approach to find maximum loadability limits of the power system has ability to provide an optimal solution. The proposed approach is tested on 30-bus, 118 bus and 300-bus systems. The results are compared on various parameters with existing methods and base case. The quality of solution obtained for test systems is better than other existing techniques. On comparison it is found the maximum loading limit using proposed approach is more than other existing methods while voltage constraint is within its limits. From statistical analysis it is found that the mean and worst results obtained using proposed approach are better than other methods for small size of population and less number of iterations. On comparing the computational time it is found that the proposed approach takes more time because of step increase of load in LIA. But it does not limit the effectiveness and applicability of proposed approach to big size network. The effectiveness of suggested approach on large network of 300-bus system is analyzed which provides quality solution.