IEC 62366: usability engineering that actually reduces use error
Standard & Framework · Human Factors
IEC 62366-1:2015+AMD1:2020 requires a use-related risk analysis that walks the ISO 14971 hazard analysis to find critical tasks, and FDA can expect the summative usability evidence for those tasks in a 510(k) or PMA.
What does IEC 62366 require for medical device software?
IEC 62366-1 requires a use-related risk analysis that walks the ISO 14971 hazard analysis to find critical tasks. FDA can expect summative usability evidence for those tasks in a 510(k) or PMA.
The one distinction most usability write-ups miss
General usability asks "can a user complete the task." IEC 62366's use-related risk analysis asks a narrower, harder question: for each critical task — one whose failure or delay could cause serious harm — can a representative user population complete it without a use error the interface fails to make correctable in time? A device can be pleasant to use and still fail this test.
Identifying critical tasks
In MedTech usability engineering, a task is critical if a use error performing it could plausibly lead to serious injury — determined by walking the device's ISO 14971 hazard analysis and asking, for each hazard with a software or UI contributing cause, which user task sits upstream of it.
Use-related risk analysis worksheet
| Task | Critical? | Potential use error | Harm if uncorrected | Mitigation (UI/design) |
|---|---|---|---|---|
| Confirm infusion rate before start | Yes | Confirms without re-reading displayed rate | Over/under-infusion — serious injury | Forced two-step confirmation showing rate in large text; no default-accept |
| Silence a non-critical alarm | No | Silences wrong alarm | Minor — alarm re-triggers | Alarm-specific silence control, not global |
| Acknowledge a critical alarm | Yes | Acknowledges without addressing underlying condition | Delayed clinical response — serious injury | Acknowledgment does not clear the underlying condition indicator |
Summative usability testing
Formative (early, iterative) testing informs design. Summative testing is the evidence artifact: a representative sample of intended users, in a simulated use environment, attempting each critical task under realistic conditions (including realistic distraction and fatigue where applicable), with every use error and close call recorded — not just task completion rate.
Engineering reference only. Not formal regulatory counsel. FDA's 2016 human factors guidance and IEC 62366-1 should be consulted directly for a specific submission.
Useful next step
Provenance & review state
- Last reviewed
- Sources
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- IEC 62366-1:2015+AMD1:2020 — International Electrotechnical Commission
- FDA Applying Human Factors and Usability Engineering to Medical Devices (2016) — U.S. Food and Drug Administration
- ISO 14971:2019 — International Organization for Standardization
- Ingested from
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