According to the PMBOK Guide, quality assurance is the process of auditing the quality requirements and the results from quality control measurements to ensure that appropriate quality standards and operational definitions are used. Quality assurance helps to identify and correct any deficiencies in the project processes and deliverables. In this scenario, the project manager should perform quality assurance to review the processes against the quality management plan and identify the gaps that led to the missing documents and approvals. This will help to ensure that the project is compliant with the quality standards and prevent future nonconformities. References: PMBOK Guide, 6th edition, page 288-289. PMP Questions page 495, question 495. How To Find The Correct Answer On PMP Exam Questions.