The energy system performance could be enhanced by using the Flexible AC transmission System (FACTS) devices such as, Interline Power Flow controller (IPFC) and Static Series Synchronous Compensator (SSSC). Because of its considerable cost, it is very important to limit the amount of these controllers and locate them optimally in the ability system to be able to achieve an improved utilization of FACTS devices. Firstly, we've applied optimization techniques, namely, Artificial Neural Network (ANN), Elitist Nondominated Sorting Genetic Algorithm(NSGA-II) and Perturb and Observe Method Algorithm (P&O) to learn the perfect amount of multi-devices of Interline Power Flow Controller and Static Series Synchronous Compensator to be able to improve the device loadability and to ensure the steady state security of the network. Secondly, we performed a contingency analysis procedure based on severity index (SI) to spot and classify the absolute most severe line contingencies. Then, we determined the perfect placement and parameter setting of FACTS devices in power system by using the above optimization approach to ease the line overloads. To guarantee the robustness and effectiveness of the proposed method, the optimization problem presented in this paper aims at reducing FACTS installation cost and decreasing total real and reactive power losses.