In this book a model formulation technique uses the swarm intelligence population based ABC algorithm in its procedure to obtain stable and approximate low order model for the Original higher order discrete systems. The quality of a formulated low order model is judged by designing the PID Controller. PID controller of the formulated low order model efficiently controls the original higher order system. This approach minimizes the complexity involved in direct design of PID controller for higher order discrete systems. The algorithm is simple to implement and computer oriented.