<p>Designing a controller for a process plant typically modeled as a first or second-order system with dead time involves an efficient and accurate estimation of its parameters. Since many process plants are characterized as second-order plus dead time (SOPDT) overdamped or critically damped systems, this study presents a straightforward parameter estimation method using transient response data from a step input at three specific time instants. Two-time domain performance indices (PIs), <span></span><math>