Moumen, what do you by how to check if Quality Plans are accurate prior to use? Do you mean implementing a quality plan for a product line? In my experience, a quality plan would be a document reviewed and approved/accepted by a group of individuals that have the most knowledge and qualifications to determine if the quality plan is sufficient. Applying controls to the use of quality plans would be a circular activity in my mind. You should refer to ISO 10005 that gives good content and information behind how to implement and use quality plans in a management system.