PID controller is one of the most robust and well-implemented controller in today's industry. However, the advancement of technology has urged the industry to improve overall process in term of its overshoot, rise time, settling and other domains. In this paper, Particle Swarm Optimization (PSO) algorithm is implemented to optimize the controller parameters in order to improve the system performance of the real pressure plant. Simulation and experimental work are carried out side by side to prove the feasibility of the PSO method. The results show that PSO had successfully improved the system performance of the real pressure plant by 35.44 if compared to Cohen Coon tuning method. © 2018 IEEE.