A team member proposes an improvement to product attributes that adds customer value and reportedly won't affect schedule or cost. What should the project manager do?

The correct action is to ask the team member to file a formal change request. Even if a proposed improvement appears to have no impact on schedule or cost, it still represents a change to the product scope or attributes. All changes, regardless of perceived impact, must follow the project's established change control process to be properly evaluated, approved, and integrated. This ensures that the change is documented, assessed for any unforeseen consequences, and formally authorized before implementation, maintaining project control and preventing scope creep. Dismissing the suggestion is counterproductive and stifles innovation. Accepting it without formal review bypasses necessary controls. Having another team member validate the suggestion is part of the evaluation process, but it doesn't replace the need for a formal change request to initiate that process.