Consider you are driving a car from your home to your office and you want to reach your destination in the least possible time. Here, the system includes both the car and the route between your home and office. The question is, how should you press the accelerator pedal and change the gears in order to minimize the total traveling time? The optimality criterion can be defined as the minimization of the total traveling time, through controlling the speed and shifting the gears, subject to satisfying limited numbers of constraints such as availability of the fuel and traffic conditions. This problem formulation usually represents a controlled dynamic system which can be explained by the optimal control theory (Hocking 1991).