Control Scope process falls in the Scope Management Knowledge Area under the Monitoring and Controlling Process Group

Control Scope basically contains two things,
- measuring and assessing the Work Performance Data against the Scope Baseline
- managing any changes to the Scope Baseline
Steps of Control Scope Process
- Work Performance Data quantifies the completed project work which can then be compared against the Scope Baseline (Scope Baseline = Project Scope Statement + Work Breakdown Structure + WBS Dictionary)
- Once this measurement is in place, the magnitude of variance (if any) can be determined
- The next step is to decide if a corrective action or preventive action or defect repair is needed to bring the project back on track
- If a Change Request is needed to fix the variance and conform to the scope baseline (always remember that corrective action, preventive action and defect repair are major causes of a change, read this for more), the impact of the change on project constraints needs to be evaluated and the change needs to be approved through the Change Management process
- Finally, the project work is re-planned and the documents are re-baselined
By the way, did you notice ‘preventive action’ in point 3 above? Any thoughts on how that appeared?
Actually, there could be instances on the project whereby following the project management plan itself could invite trouble. What it means is that the project management plan itself is flawed. Let’s say you estimated that a work package can be accomplished in two weeks but later realized that it will actually take 6 weeks of effort. Time to Control Scope!
At this point, it is important to understand that as a Project Manager you might get overwhelmed with Change Requests veiled as ‘preventive actions’. This is where you need to keep tab on the scope baseline and your Requirements Traceability Matrix (RTM) can be the best weapon against such unnecessary changes. This is how you would actually ‘Control’ the Project scope.
As mentioned earlier, you might see Control Scope before Validate Scope in certain texts but do note that while Validate Scope typically happens once the deliverable is ready, Control Scope can happen at any time. It is an extremely pro-active process
Check more articles on Scope Management