Some of those outputs are:

• CR: "increase effectiveness of the policies, processes, and procedures of the performing organization." (source PMBOK)
• Project management plan updates
• Project document updates:
• Organizational process assets updates.

1) I have read that approved CR are not implemented by this process but by the direct and manage execution process. In this case, why are the project management plan, project documents an output of the perform quality assurance process?