Where do changes come from? For an average Project Manager, the most common reason that leads to a change request is an addition in the baselined scope of the project. Someone somewhere needs a new feature and that brings about a change request. But to understand the concept of change requests, its important to understand Preventive and Corrective actions as well as Defect Repair that are the most common causes of a change.
Preventive Actions This could be a result of risk management. Let's assume the technology that the project team is working on is set to undergo a major upgrade. The project team will most certainly require training to continue the work on the project. This training will obviously impact the baselined cost and schedule of the project and thus require a formal change request. Defect Repair Defect Repair is also sometimes referred to as Rework. This is the work required to rectify the defects that may come up during the course of the project. Fixing a substantial error from a piece of code, for instance, will require additional time and could also lead to additional cost.
Corrective actions While fixing an error is defect repair, making sure the error doesn't occur again i.e. root causing and fixing it is the essence of corrective action. So while preventive actions make sure that things don't go wrong at all, corrective actions make sure that once something has gone wrong, it doesn't repeat itself. Clearly, corrective action is a reactive approach while preventive action is proactive approach. Another point of difference is that Preventive and Corrective actions are taken to avoid variances in baselines as well as the Project Management Plan meanwhile Defect Repair is done to fix a deliverable.
At this point, let us remind you that the change management plan is an element of the project management plan and it clearly defines how changes will be handled in the project. That being said, you will be managing changes to the project from its inception until the final closure and thus a successful project requires a thorough change management plan. More Integration Management Articles