What does an auditor check for IEC 62366?

IEC 62366-1:2015 + AMD1:2020 · Usability engineering file & traceability

The short answer

For IEC 62366, an auditor mainly checks the completeness of the usability engineering file and end-to-end traceability: use specification, user interface specification, analysis of known use problems, hazard-related use scenarios, and records of formative and summative evaluations — plus the trail from use errors through risk controls (ISO 14971) to summative test results.

What the auditor looks at

Use specification: user groups, use environment, intended use complete
User interface specification: safety-related requirements derived
Known use problems: analysed (including from predecessor/comparator devices)
Hazard-related use scenarios: identified and prioritised
Formative evaluations: documented, with resulting design changes
Summative evaluation: records, acceptance criteria, results
Traceability: use error → risk control (14971) → summative test result

The most common weakness

Incomplete traceability. Auditors want to see the continuous trail — from an identified use error, through the risk control, to the summative test result proving the control works. medairon helps you document these links in a structured, auditable way.

Also checked: justification of the sample

The auditor expects a justification of the chosen user groups and the summative sample size. The widespread "~15 per user group" is FDA practice, not a 62366-1 requirement — your justification must match your user groups.

Frequently asked questions

What is the single most important document?

The usability engineering file as overall evidence — it brings together specifications, scenarios, evaluations and traceability. Without the continuous trail, even a thick single document helps little.

Does the auditor test the device itself?

Primarily, the auditor reviews the file and the evidence. Actual operability is demonstrated through your summative evaluation results — the auditor assesses whether that evidence is complete, plausible and traceable.