The requirements sign-off is a process that involves obtaining the formal approval and acceptance of the requirements from the customer and other stakeholders. The requirements sign-off confirms that the requirements are clear, complete, correct, and consistent, and that they meet the customer's needs and expectations. The requirements sign-off also establishes a baseline for the development and testing of the solution, and serves as a reference point for managing changes and resolving issues.The business analyst should first facilitate the requirements sign-off with the customer before the developers start development, to ensure that the requirements are agreed upon and validated by all parties, and to avoid rework, delays, and conflicts later in the project.Reference: PMI Professional in Business Analysis (PMI-PBA) Examination Content Outline1, page 18; Business Analysis for Practitioners: A Practice Guide2, page 92.