The processes of monitoring a plan's implementation and taking corrective action as needed are referred to as controlling. Control is usually achieved with the use of feedback. Feedback is information that can be used to evaluate or correct the steps that are actually being taken to implement a plan. Based on the feedback, a manager may decide ti let the implementation continue as is, take corrective action of some type to put the action back in harmony with the original plan, or do some midstream replanning.