How do you calculate a cleanroom compliance risk score?

Multiply the three ratings together: severity x occurrence x detection. With a severity of 8, occurrence of 3, and detection of 5, the score is 8 x 3 x 5 = 120 on a 1-1000 scale.

What is a good cleanroom compliance score?

Lower is better. On a 1-10 scale per factor, scores under ~40 are typically monitor-only, 40-100 warrant a planned action, and anything above 100 — or any item with severity 9-10 regardless of total — should trigger immediate CAPA.

Why does detection weakness raise the score?

A high detection score means your controls are unlikely to catch the gap before product is affected. A latent contamination route that no routine monitoring would flag is far more dangerous than an obvious one, so it multiplies the risk upward.

Is this the same as an FMEA RPN?

Yes, structurally. It is the classic FMEA risk priority number (severity x occurrence x detection) tuned with cleanroom-specific scoring anchors for things like viable counts, gowning breaches, and HEPA integrity.

Should I act on severity alone instead of the total?

Use both. Best practice is to set a severity threshold (e.g. any 9 or 10) that forces action irrespective of the multiplied total, because a rare but catastrophic sterility failure can score low overall yet still be unacceptable.

How often should I rescore?

Rescore after each CAPA closure and at scheduled risk-review intervals. Detection ratings in particular should drop once you add monitoring or alarms, which lets you demonstrate measurable risk reduction to auditors.

Cleanroom & Contamination Control calculator

Cleanroom Compliance Score Calculator

The Cleanroom Compliance Score is a risk priority number (RPN) adapted for cleanroom and contamination-control programs. Quality engineers, microbiologists, and validation leads use it to rank gaps found during environmental monitoring excursions, gowning audits, or HVAC/HEPA deviations so the highest-risk items get CAPA resources first. By forcing severity, occurrence, and detectability onto one consistent scale, it turns a pile of audit observations into a defensible, sortable list. It matters because cleanroom failures rarely announce themselves — the dangerous ones are the gaps you can't readily detect until a sterility test fails.

What this calculator does

Score compliance risk for cleanroom classification, monitoring, pressure cascade, cleaning, gowning, training, and deviation controls.
a team needs to prioritize compliance remediation before product release, customer audits, or regulatory inspection for a cleanroom compliance review
It multiplies a compliance impact severity score by a gap occurrence score and a control detection weakness score to produce a single contamination-control risk priority number.

Formula used

Cleanroom Compliance Score risk score = compliance impact severity score × compliance gap occurrence score × control detection weakness score
Use the same scoring scale across comparable cleanroom and contamination-control risks.

Inputs explained

Compliance impact severity score:
Compliance gap occurrence score:
Control detection weakness score:

How to use the result

Use it when triaging environmental monitoring excursions, gowning or behavior audit findings, particle count trends, or any cleanroom deviation that needs prioritization across an FMEA or risk register.
It is an ordinal ranking, not a probability — a score of 120 is not literally twice as risky as 60, and identical totals (e.g. 8x5x3 vs 5x4x6) can hide very different risk profiles, so always review the underlying severity driver.

Current U.S. benchmarks

Industrial electricity averages 8.66 cents per kWh across the U.S. (EIA, Apr 2026), up 5.5% from a year earlier. Energy-intensive steps carry this directly into unit cost.
U.S. manufacturing runs at 75.6% of capacity (Federal Reserve, May 2026). New factory orders are up 2.3% year over year (Census).

Common questions

How do you calculate a cleanroom compliance risk score? Multiply the three ratings together: severity x occurrence x detection. With a severity of 8, occurrence of 3, and detection of 5, the score is 8 x 3 x 5 = 120 on a 1-1000 scale.
What is a good cleanroom compliance score? Lower is better. On a 1-10 scale per factor, scores under ~40 are typically monitor-only, 40-100 warrant a planned action, and anything above 100 — or any item with severity 9-10 regardless of total — should trigger immediate CAPA.
Why does detection weakness raise the score? A high detection score means your controls are unlikely to catch the gap before product is affected. A latent contamination route that no routine monitoring would flag is far more dangerous than an obvious one, so it multiplies the risk upward.
Is this the same as an FMEA RPN? Yes, structurally. It is the classic FMEA risk priority number (severity x occurrence x detection) tuned with cleanroom-specific scoring anchors for things like viable counts, gowning breaches, and HEPA integrity.
Should I act on severity alone instead of the total? Use both. Best practice is to set a severity threshold (e.g. any 9 or 10) that forces action irrespective of the multiplied total, because a rare but catastrophic sterility failure can score low overall yet still be unacceptable.

Last reviewed 2026-05-12.