Compo and morari (1989) have used a standard flow control objective, that is to minimize the maximum rete of change of outlet flow (MRCO) of the tank under consideration, with constraints that the level should not violate upper or lower bounds over some prediction horizon. These authors successfully applied a MPC algorithm to this problem. In this, a simple internal model predicts the future behavior of the tank based on the past two level measurements, and the previous outlet flow, as outlined in the level equation (1), below