By definition (as per 21 CFR Part 820.75), validation is ‘establishing documented evidence that provides a high degree of assurance that a specific process will consistently
produce a product meeting its predetermined specifications and quality attributes.’
This validation is done to prove that equipment and processes consistently do what
they are supposed to do. Once processes have been validated, it is important to maintain this validated state: a change control system should be in place to document all
changes to facilities, equipment, or processes that may have an impact on product
quality. Evaluation of the impact of the change should be performed to the extent of
revalidation defined