Review of Measurement Uncertainty budgets is based on the department and individual assay requirements. Depending on the method of assessment review will vary from 6 monthly to 1 yearly. Any such changes are discussed at a departmental level and ratified by the experts in the assays being discussed.
A variation of the Procedure for Uncertainty Management (PUMA) system may be decided to be used by individual laboratories for individual assays to review and improve analytical processes. This is by no means compulsory.
In addition if any significant changes occur in any of the contributing factors then a reassessment will be performed. When assessing by IQC, any change in the performance of the IQC will indicate a requirement to re-evaluate the MU.