Final answer:
An individual's previous PQS qualification generally remains valid after a revision, but they may need to qualify in the new or revised sections only, or requalify completely depending on the changes and the significance of the PQS to their role.
Step-by-step explanation:
When an individual has qualified on a Personal Qualification Standard (PQS) and that PQS is subsequently superseded by a revision, the individual's qualification on the previous version typically remains valid. However, the individual may be required to complete only the new or revised portions of the PQS in order to stay current with the most recent standard. The process may entail a review of the revisions by the individual in coordination with their supervisor or PQS coordinator. If significant changes have occurred, or if the qualification is deemed critical for the individual's current duties, requalification on the entire new PQS may be necessary. Supervisors usually have discretion based on the extent of the revisions and the critical nature of the specific PQS to an individual's job performance.