A product update, new data source, wider rollout or unexpected outcome can change the original decision. The point is not to restart every assessment. It is to check whether the change affects the conditions, controls or approval that were already in place.
Know what should trigger review
Common triggers include a new purpose, changed supplier terms, new personal or sensitive information, a broader group of users, increased automation, an incident or evidence that the system is not performing as expected.
Focus on what changed
Keep the earlier assessment and record the new facts beside it. The owner and reviewers can then see which controls still apply, what needs updating and whether a fresh decision is required.
Make change visible to management
A current register should show uses that have changed, are under review or have overdue actions. This gives management and the board a clearer picture than a report that only counts approved systems.