It is a system in which preventive action is being taken for smooth operation, It is always used along with the feedback, as it require keep monitoring of set point and suppression of unmeasured disturbance in any process.
By using this method performance of system can be improved as compared to simple feedback control system.
In any system where there is major disturbance that can be measured before it affect s the process output, it is ideal for eliminate the affect of disturbance on the process output.