Identification of user interface characteristics related to safety and associated potential use errors — using task analysis and cross-reference to the use specification — is the foundational use-error input to hazard identification.
AMD1:2020 clarified the primary operating functions scope (only when specified in product-specific safety standards) and updated the ISO 14971 cross-reference from 2007 §4.2 to 2019 §5.3.
Task analysis documentation linking each UI characteristic to a specific task, user profile, and potential use error — a static characteristics list without task context does not satisfy the clause.
Maps to
IEC 62366: §5.2 Identify USER INTERFACE characteristics related to SAFETY and potential USE ERRORS
ISO 13485: §7.3.3 Design and development inputs
ISO 14971: §5.3 Identification of characteristics related to safety
Requirement text
The manufacturer shall identify user interface characteristics that could be related to safety as part of a risk analysis performed according to ISO 14971:2019 clause 5.3. This identification may also be performed using the tools and techniques from the usability engineering process. This identification shall include consideration of the primary operating functions, if they are provided in applicable particular product-specific medical device safety standards. Based on the identified user interface characteristics and use specification, the manufacturer shall identify the use errors that could occur and are related to the user interface. This identification may be accomplished by conducting a task analysis. The results of this identification of characteristics related to safety and potential use errors shall be stored in the usability engineering file.
Why this clause exists
Clause 5.2 exists because hazard identification in standard ISO 14971 risk analysis tools does not systematically surface user interface characteristics as hazard sources. FMEA and fault-tree analysis are structured around component failure modes, not around the perceptual and cognitive properties of an interface that make use errors more or less probable. A display with a 6-point font, a control that requires simultaneous two-hand operation under time pressure, or an alarm with insufficient volume for a noisy clinical environment are interface characteristics that are predictable use-error precursors — but they are invisible to component-level failure analysis. IEC 62366-1 clause 5.2 requires a dedicated, explicit identification step that examines the user interface itself as a safety-relevant design element, separate from the device’s mechanical or electrical failure analysis. The task analysis obligation was added because interface characteristics in isolation do not predict use errors — the interaction between a characteristic and a task performed by a specific user in a specific environment is where use-error probability arises. Without task analysis, a manufacturer cannot systematically identify which interface elements, in which task contexts, create use-error risk for the specific user profiles described in the use specification.
What changed
IEC 62366-1:2015+AMD1:2020 CSV clause 5.2 was substantively updated by AMD1:2020. The 2015 edition required identification of UI characteristics related to safety with consideration of ‘primary operating functions’ from applicable safety standards — AMD1:2020 retained this but clarified that the primary operating functions consideration applies only ‘if they are provided in applicable particular product-specific medical device safety standards.’ Additionally, the AMD1:2020 update revised the ISO 14971 cross-reference from ISO 14971:2007, 4.2 to ISO 14971:2019, 5.3. The core obligation — identify UI characteristics related to safety and resulting potential use errors, store results in the usability engineering file — is unchanged.
Common gaps (what we see in audits)
- UI characteristics identified without task context — Manufacturers identify interface characteristics (small font, low contrast, complex menu hierarchy) in a static review without linking each characteristic to a specific user task, user profile, and use environment where it creates use-error risk. Without the task context, the list of characteristics cannot drive hazard identification and is not useful for evaluating risk control options.
- Use error identification based on designer assumptions rather than empirical observation — Use error identification conducted by the design team alone, without representative user input or task analysis methods, systematically misses use errors that arise from users’ knowledge gaps, cognitive shortcuts, and negative transfer from other devices. Designer-led analyses underestimate use-error probability for the most hazardous interaction patterns.