What is impact verification in manufacturing?

Impact verification is also called verification of effectiveness, or VOE. It separates two things teams treat as one: that an action was completed, and that it actually worked.

1How does impact verification work?

Impact verification runs after a change is implemented and before the action is closed. It tests one question with evidence: did the change deliver the result it was meant to? The work breaks into five steps.

1. Define the success metric. Agree the indicator that proves the problem is solved, such as defect rate, scrap, downtime or complaint count, and the target it must reach.
2. Record the baseline. Capture the metric’s value before the change, so the after state is compared against a real starting point, not an impression.
3. Set a verification window. Decide how long to observe, often 30 to 90 days or a set number of production runs, long enough for recurrence to show if the fix did not hold.
4. Measure after the change. Collect the same metric across the window and check the problem has not reappeared, not just a single favourable data point.
5. Close or reopen. If the metric meets the target and stays there, close the action with the evidence attached. If it does not, reopen and return to root cause analysis.

The verification window is what makes the step meaningful. A problem that returns later was never solved, only paused.

2Why does impact verification matter for manufacturing?

Without impact verification, a quality system records activity rather than results. Teams log fixes, close the paperwork, and never learn which fixes failed. The recurring problem resurfaces as a new report, and the same effort is spent twice.

ISO 9001:2015 makes this explicit. Clause 10.2.1 requires the organisation to review the effectiveness of any corrective action taken, which is impact verification in standards language. Auditors treat closing a corrective action without confirming the non-conformity stopped recurring as one of the most common findings, because it breaks the closed-loop improvement the standard is built around.

3Impact verification vs action completion: what is the difference?

The most common mistake is closing an action when the task is done rather than when the result is confirmed. Completion is an input. Verified impact is the outcome. Closing on completion quietly lets unresolved problems back into the operation.