What makes a barrier critical
- Nothing else stands behind it on that pathway.
- It stops several pathways at once, so its failure opens several doors.
- It sits on the pathway with the heaviest consequence.
What the plan records
| Field | Content |
|---|---|
| Owner | A named role, not a person — the role accountable for the barrier working |
| Test method | How it is proven: function test, observation, record review |
| Frequency | How often the test is repeated |
| On failure | What restriction applies if the test fails |
The last row matters most
If "what happens when the test fails" is not written down, the test itself means nothing. When a critical barrier fails its test, either work stops, or a temporary barrier goes in, or the risk is accepted in writing. A fourth option — doing nothing — is the one most often taken, precisely because it is never recorded.
The list stays short
A site may have hundreds of controls but its critical barriers are counted in tens. A short list is a list people follow; declaring every barrier critical has the same effect as declaring none of them critical.
What an audit asks
Where a critical barrier list exists, an audit follows one chain: does the list exist, does every line carry an owner and a test frequency, are the last test records there, and can you see what happened after a failed test.