Proper engagement supervision is documented through formal records that show a systematic review and oversight process. A completed engagement workpaper review checklist provides evidence that the supervisor has reviewed and approved the work done by the audit team. This formal checklist ensures all critical aspects of the engagement are reviewed systematically, meeting the standards for proper supervision documentation. Reference:
"Internal Auditing: Assurance & Advisory Services" (The Institute of Internal Auditors)
"International Standards for the Professional Practice of Internal Auditing" (IIA)