IEC 62366-2

Technical report instead of a standard: the difference in status

The difference between a standard and a technical report is more than a formality. IEC 62366-1 sets requirements: Anyone developing according to this standard must carry out and demonstrate certain steps. IEC 62366-2 sets no requirements of its own but explains, justifies and illustrates the requirements of Part 1, comparable to a practice-oriented explanatory document on implementing these requirements. The approaches described there can serve as recognized examples; a manufacturer does not have to justify why it deviates from Part 2, but why its approach meets the requirements of IEC 62366-1.

For conformity assessments this means: A notified body checks compliance with IEC 62366-1, not with IEC 62366-2. Anyone who deviates from the approaches described in Part 2, however, should be able to justify why the chosen approach still meets the requirements of Part 1. The report can serve as orientation without being binding itself.

What IEC 62366-2 provides in terms of content

The report accompanies the entire usability engineering process and provides in-depth guidance on practically every step:

• Context and user research: Techniques for collecting information on user groups, tasks and use environment, including guidance on task analysis.
• Formative methods: Analytical and empirical methods such as cognitive walkthrough and think-aloud, with guidance on advantages and disadvantages.
• Participant selection: Criteria for representative samples and for dealing with heterogeneous user groups.
• Use environment: The systematic consideration of use environment factors in test designs.
• Summative evaluation: Guidance on sample size, success criteria and the handling of observed use errors.

For existing products, Part 2 gives only supplementary guidance: Many manufacturers face the question of how to deal with products that have been on the market for many years and for which historical process documentation is incomplete. The normative approach for this is in IEC 62366-1 Annex C (User Interface of Unknown Provenance, UOUP); IEC 62366-2 contains guidance on adapting the usability engineering effort for existing products and for changes to existing user interfaces.

Help with choosing methods

The practical value of the report lies less in new content than in putting existing methods into context. IEC 62366-1, for example, requires formative evaluations without prescribing a particular method. IEC 62366-2 discusses when an analytical method is sufficient and when an empirical test with users is indicated, and names typical pitfalls of each method.

This guidance is particularly valuable for teams going through the process for the first time. It protects against two opposite errors: a methodologically excessive approach that ties up resources without additional insight, and an approach that is too lean and does not stand up before a notified body or authority.

Interplay with risk management

One particular focus of the report is the interface with risk management according to ISO 14971. IEC 62366-1 requires this interplay but describes it only in outline. IEC 62366-2 explains more concretely how risk control measures are derived from the findings of the use-related risk analysis and how their effectiveness is subsequently verified in the summative evaluation.

In practice, this interplay is a frequent weak point: The use-related risk analysis and the risk management file are maintained by different teams and drift apart. The report makes clear that both documents must refer to each other throughout so that a notified body can check traceability.

Practical benefit and limits

The report does not replace professional judgment of one's own. It describes general approaches and examples that cannot be transferred unchanged to every product. An implantable product with professional users makes different demands on the choice of methods than a self-testing device for lay users. The responsibility for selecting and justifying, from the options described, the one appropriate for the specific product remains with the manufacturer.

Likewise, the report does not replace knowledge of the underlying disciplines. It refers, for example, to ergonomic and cognitive psychology foundations without conveying them comprehensively itself. For these, ergonomics remains the authoritative body of knowledge in its own right.

Regulatory reference

IEC 62366-2 itself carries no normative obligation and is not used by notified bodies as a standalone test benchmark. Compliance with IEC 62366-1 is assessed. In practice, however, the approaches described in the report can serve as orientation when the appropriateness of a choice of methods is assessed. The approaches described can also help manufacturers implement MDR-relevant requirements on usability and use-related risks.

The FDA human factors guidance pursues a comparable purpose for the US market but is organized as a guidance document of the authority itself and not as an international report. Manufacturers supplying both markets usually compare the two documents against each other to avoid duplicate work.

Frequently asked questions (FAQ)

Sources

• IEC 62366-1:2015+AMD1:2020, Medical devices, Part 1: Application of usability engineering to medical devices
• IEC/TR 62366-2:2016, Medical devices, Part 2: Guidance on the application of usability engineering to medical devices
• ISO 14971:2019, Medical devices, Application of risk management to medical devices
• Regulation (EU) 2017/745 on medical devices (MDR)
• FDA Guidance: Applying Human Factors and Usability Engineering to Medical Devices

Related terms

• IEC 62366-1
• Task analysis
• Formative usability evaluation
• Use-related risk analysis (URRA)
• Use environment factors
• Risk management (ISO 14971)

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