So if the exam question asks us what 's the difference in the Quality assurance vs the Quality control process the answer is the FOCUS right?
As you said PMBOK explains that these processes can inspect both the deliverables and the processes. So if a question asks us which process inspects the process of the quality plan the answer is...Quality Assurance. Despite the fact that Quality control does the same thing but not with the same focus.
That’s a great question. Quality Control is related to inspecting project deliverables by the project team. The deliverables are inspected against the quality requirements. If the project team is satisfied, it conducts another inspection with the customer of the project during the Verify Scope process. Both the Quality Control and Verify Scope processes can be performed together.
The Quality Assurance is to inspect the processes, procedures and the project management approach to ensure that these are well capable of producing quality deliverables. Yes you are right that the focus over here is on the process while the focus of the quality control is on the deliverables. Usually quality assurance is not done by the project team and rather by an external entity.
Although the focus on Quality Control is on the deliverables and the focus of Quality Assurance is on the processes, both the processes can inspect both the deliverables and the processes. For example during a Quality Control inspection by a project team, it is noted that the project documents being prepared are not of acceptable standards. At this point the project team will also look into the root cause, that is the process of producing these project documents. However, still the focus is on the deliverable, i.e., the project documents in this case.