I know that in Canada, once a CCP is VALIDATED and doe not change you never need to perform the complete validation again. Monitoring and on site verification gets done as per the stated frequency.
From the FSEP manual. The FSEP manual is worded to work directly with Codex...I hope this helps.
Validation – Obtaining evidence that a control measure, if properly implemented, is capable of controlling the hazard to a specified outcome.
Verification – A company’s use of methods, procedures, tests and other evaluations, in addition to monitoring, to determine its conformance to and the effectiveness of its HACCP system.
3.3 Validation Every establishment shall demonstrate that the critical control points are capable, on a consistent basis, of achieving the intended level of hazard control. Validation is performed at the time the CCP is designed, or when changes indicate the need for re-validation. Validation of a CCP is, whenever possible, performed before it is fully implemented. Depending on the CCP that is being validated, the validation documentation may include: • Scientific, technical or regulatory support to demonstrate that the selected critical limit is effective for control of the hazard; • Commissioned testing data specific for a piece of equipment (e.g. pasteurizer) to demonstrate that the equipment is capable of meeting the selected critical limit; • Supporting data to demonstrate that the monitoring procedures are effective enough to detect loss of control at a CCP before the finished product leaves the control of the producing establishment.