A Periodic Review is essential to ensure the validated state of an automation system. In general a periodic review is scheduled every two years.

Subjects for review are:

• Documentation (complete, correct, up to date)
• Change of use
• Level and nature of changes
• Outstanding actions
• Previous reviews, reports, audits
• Prove of unstable or unreliable operation
• Changes in circumstances
• Regulations, environment, product, business, best practices, personnel
• Procedures, incident logs
• Software and data backups

 A Periodic Review may be part of an internal audit. The results of the Periodic Review can be used for external audits.