During project closing, the project manager finds one deliverable does not meet customer expectations. How should the project manager proceed?

The project manager's first step should be to understand the discrepancy. Reviewing the deliverable requirements and customer approval criteria (from the project management plan) will clarify if the deliverable truly fails to meet agreed-upon standards or if there's a misunderstanding. This factual assessment is crucial before taking further action. Asking the customer to submit a change request is premature; the project manager needs to determine if a change is actually needed or if the deliverable is compliant. Meeting with the customer to agree on a deliverable scope is also premature and implies the scope is negotiable at this late stage, which it typically isn't. Contacting the project sponsor for negotiation is an escalation that should only occur after the project manager has fully assessed the situation and attempted to resolve it directly.