Does every device need a summative usability study?

No. The scope of usability engineering activities should be proportionate to use-related risk. Simple, low-risk devices may need only a streamlined formative evaluation, while devices where use error could cause serious harm typically require a full summative validation study.

How does usability engineering connect to risk management under ISO 14971?

IEC 62366-1 explicitly interfaces with ISO 14971: use-related hazards and hazardous situations identified through usability engineering feed into the device's overall risk management file, and mitigations affecting the user interface are verified through usability evaluation rather than solely through engineering testing.

All terms

StandardsQuality System

Usability Engineering

The systematic process, defined in IEC 62366-1, for analyzing, specifying, designing, verifying, and validating the usability of a medical device to minimize use-related risk.

Reviewed by Christian Espinosa, Founder, Blue Goat CyberLast reviewed September 19, 2026

Definition

Usability engineering, also called human factors engineering, is the process standard IEC 62366-1 defines for identifying user interface characteristics related to safety, identifying and evaluating hazard-related use scenarios, and applying verification and validation activities to ensure a device can be used safely and effectively by its intended users, uses, and use environments. The process integrates with ISO 14971 risk management: use errors that could lead to a hazardous situation are analyzed, design mitigations are applied to the user interface, and formative evaluations (iterative, exploratory testing during design) precede a final summative (validation) usability evaluation conducted under simulated or actual conditions of use before market release.

What the regulation says

FDA's guidance 'Applying Human Factors and Usability Engineering to Medical Devices' (2016) describes the expectation for a human factors engineering report summarizing formative and summative testing, critical task identification, and use-related risk analysis to support a premarket submission.

What this means in practice

FDA's human factors guidance, applicable to devices FDA has flagged as needing human factors data (including many combination products, infusion pumps, and other devices where use error could cause serious harm), expects a summative usability study with a representative user population, defined critical tasks, and root-cause analysis of any use errors or close calls observed. IEC 62366-1:2015 plus its Amendment 1:2020 is the internationally recognized and FDA-recognized consensus standard; IEC/TR 62366-2 provides non-mandatory guidance on applying the process.

Common pitfalls

•Conducting only formative usability testing and skipping a rigorous summative (validation) study before submission, when the device involves tasks FDA or a notified body considers safety-critical.
•Defining critical tasks too narrowly, omitting steps where a use error, though less obviously safety-related, could still lead to a hazardous situation under IEC 62366-1's use-related risk analysis.
•Treating usability engineering as a labeling and instructions-for-use exercise rather than a design-input activity that should influence the user interface from early development.

Frequently asked questions

The terms are used largely interchangeably in medical device regulatory practice; IEC 62366-1 uses 'usability engineering' while FDA guidance more often uses 'human factors engineering,' but both describe the same underlying process framework.

Grouped by theme

Editor's picks

· Hand-selected related concepts

Standards

IEC 62366-1

Application of usability engineering to medical devices.

Standards

ISO 14971

International standard for the application of risk management to medical devices.

Clinical & Trials

Human Factors Engineering(HFE)

Engineering discipline focused on safe and effective device use by intended users.

Quality & Risk

Risk Management

The lifecycle process defined by ISO 14971 for identifying, analyzing, evaluating, controlling, and monitoring risks associated with a medical device throughout its life cycle.

Sources

3 sources

Every citation below opens the original document. Each is graded against our source-tier hierarchy so you can see what rests on binding law versus commentary.

Tier 1Binding law and standards· 1Tier 2Regulator guidance and consensus· 2

Link health: 2 verified 1 unchecked· last checked 2026-06-20

IEC·1FDA·1AAMI·1

Inline markers like [1] jump to the matching reference above.