The best practice in project management, as per the PMBOK Guide, involves confirming that all project deliverables meet the predefined acceptance criteria and obtaining formal approval from the client before considering the project or phase closed. This ensures that all requirements have been met and the client is satisfied with the outcomes, thus preventing any post-delivery issues related to unmet requirements. : = Project Management Institute. (2021). A Guide to the Project Management Body of Knowledge (PMBOK Guide) - Seventh Edition and other standards by PMI.