Keyword-PID controller, SISO system, MIMO system, Heuristic approaches, Performance analysis I. INTRODUCTION In chemical industry, most of the important processing units are highly non-linear in nature and for economical and/or safety reasons, these process loops to be operated in safe regions with the help of a PID controller [1][2][3]. Based on its operating region and its non-linearity, these loops can be modelled as SISO and MIMO systems. During the closed loop operation, optimized controller parameters for such systems are essential to minimize the waste and to maximize the production rate. Fine tuning the controller parameters for non-linear systems are highly complex than open loop stable systems. Hence, in recent years, heuristic algorithm assisted approaches are widely adopted by the researchers.