Free tool · NC treatment decision

The Proportionality Matrix

Not every nonconformity deserves a CAPA, and some need one without discussion. A common practice to rationalize your decision is the so-called risk-based approach. Traditionally, you look at a combination of occurrence and severity level, and based on the combination decide your next steps.

Deviating from the default is allowed. Deciding silently is not.

Click the cell that matches your issue

* means the default response. You can decide differently, but only with a documented rationale.

Pick a cell to see the default treatment, what to document, and when a deviation is defensible.

Illustrative examples for definitions

Severity — product (patient & user impact)

Low	No impact on safety or performance — cosmetic, packaging blemish, labeling aesthetics. The device does what it should.
Medium	Performance, usability, or reliability could degrade — the device is still safe, but it no longer fully does what it should.
High	Plausible path to patient or user harm — a safety function is affected, or misdiagnosis/mistreatment becomes possible. Reportable territory.

Severity — process & compliance

Low	Internal friction — documentation slips or minor deviations from work instructions with no downstream effect.
Medium	QMS integrity affected — a requirement not fulfilled, a control skipped, audit-finding potential. Caught before product impact.
High	A QMS control failed systematically — release without approval, data integrity breach, or a gap an auditor would rate as major.

Occurrence — qualitative

Low	Unlikely or rare — first time seen, or has rarely or never occurred in similar processes.
Medium	Has happened before, or an early trend signal is visible.
High	Recurring pattern or systemic — almost certain to happen.

Occurrence — quantitative (Example values)

Low	Single event, or < 0.1% of units/lots affected; no repeat within the last 12 months.
Medium	Roughly 0.1–1% of units/lots, or 2–3 events within 12 months.
High	> 1% of units/lots, or repeating monthly/quarterly despite corrections.

All definitions and thresholds are illustrative — calibrate them to your production volume and risk acceptance criteria.

Calibrate this to your own system. This matrix is a thinking aid for arguing proportionality — it does not replace your NC/CAPA procedure or your risk acceptance criteria (ISO 14971).

Every cell assumes a confirmed nonconformity — and a correction. The question each cell answers: does corrective action follow?

Landed on CAPA — or already have one open? Put it through the CAPA Stress Test: 28 key checks, free, in your browser. And if the decision itself is the hard part, that’s exactly what an NC/CAPA Clinic hour is for.

Take the toolkit with you

The matrix decides the treatment. Whether the record then holds up is the next question — that’s what the CAPA Stress Test toolkit is for. Subscribers get:

the full CAPA Stress Test — 78 checks across 8 sections, as an interactive page with built-in guidance and worked examples
the weak-pattern library — weak vs. improved wording for the findings auditors flag most

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