While preparing project closure and planning the next phase, a sponsor complains about quality issues in the last phase even though the quality acceptance document was signed. What should the project manager do?

The project manager should schedule a quality review meeting and include the sponsor's complaints. Even though the quality acceptance document was signed, addressing the sponsor's current concerns is crucial for maintaining stakeholder satisfaction and project success. A dedicated meeting allows for a structured discussion to understand the specific issues, their impact, and potential solutions, fostering trust and collaboration. Postponing the next phase is an overreaction and could cause unnecessary delays without first understanding the scope of the problem. Reopening formal documentation like the quality acceptance document is generally not advisable unless there's a significant, verifiable error, as it undermines the integrity of the sign-off process. While reviewing best practices and lessons learned is always valuable, it doesn't directly address the immediate stakeholder complaint about past quality issues.