The purpose of corrective action is to bring a schedule or project back on track. This can involve root-cause analysis and schedule or budget adjustments as well as expediting.
Once a change or need for corrective action is determined, the project manager must revisit and perform the following planning tasks again:
Re-baselining may be appropriate if a change is significant enough. It involves adjusting your performance measurement to the new tasks defined in the project plan. Without re-baselining, a project would appear to be significantly out of control, even though a change had been approved. Re-baselining allows management to see the progress of the project accurately after the change decision. However, re-baselining is considered a "last resort" because project historical data may be lost.