As Human Factors Engineering/Usability Engineering (HFE/UE) * becomes a core pillar of safe and effective medical device design worldwide, international manufacturers may find themselves asking, “How is usability evaluated in Japan?”
In the US, the FDA (Food and Drug Administration) requires a formal HFE/UE report for most Class II and III medical devices. Japan, by contrast, did not mandate usability engineering practices to be embedded in medical device development until recently, leading to confusion or underestimation of usability engineering’s role in regulatory success.
However, with the enforcement of JIS T 62366-1:2022 (Japan’s usability engineering standard for medical devices, harmonized with IEC 62366-1:2015) beginning April 1, 2024, usability engineering has shifted from supplementary to mandatory for all device classes. The Pharmaceuticals and Medical Devices Agency (PMDA) now has significantly increased expectations for summative evaluation, particularly for Class II and above devices.
This blog clarifies the current landscape in Japan and what it means for international teams preparing medical device submissions to PMDA.
* Commonly referred to as “usability engineering” in Japan
1. Japan’s Regulatory Approach to Usability
Japan’s medical device regulatory system is overseen by PMDA, under the Ministry of Health, Labour and Welfare (MHLW). While PMDA has published guidance documents and overview materials explaining JIS T 62366-1, these resources focus primarily on what is required rather than providing detailed implementation guidance or templates.
PMDA applies key international standards to guide usability considerations:
- JIS T 62366-1:2022 – Japan’s Industrial Standard for applying usability engineering to medical device design. Harmonized with IEC 62366-1:2015, this standard defines a structured process for identifying and minimizing use-related risks through user-centered design.
- JIS T 14971:2020 – Japan’s harmonized standard based on ISO 14971:2019 for risk management of medical devices, which includes identifying and evaluating use-related hazards.
2. What Medical Devices are Subject to Usability Engineering?
All medical devices are subject to usability engineering requirements. Like risk management under JIS T 14971, there are no exemptions from usability engineering compliance under JIS T 62366-1.
This is an important distinction: while Class I devices in Japan are generally exempt from design control requirements, they are not exempt from risk management or usability engineering.
A common misconception is that usability engineering only applies to software-based or electronically controlled devices. In reality, any medical device with user interaction falls under the scope, regardless of whether it contains software or electronics. For example, accompanying materials are also considered part of the interface and must be evaluated for use-related risks.
Examples of accompanying materials include:
- Instructions for use
- Package inserts
- Training materials
- Maintenance and inspection manuals
3. Examples of accompanying materials include:
Understanding which submission pathway applies to your device is critical for determining the level of usability engineering documentation.
| Submission Type | Device Classification | Review Authority | Summative Evaluation Expectation |
| Shonin (Approval) | New or significantly modified Class III or IV devices, and certain high-risk Class II devices | PMDA | Required – Full summative validation expected |
| Ninsho (Certification) | Standard Class II devices | PMDA-registered Third-Party Certification Body (RCB) | Typically required – Extent depends on risk profile and user interface complexity |
| Todokede (Notification) | Low-risk Class I devices | No review – notification only submitted to PMDA | Generally not required |
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For Class II devices and above, typical submission documents now include:
- Application form
- Device summary and intended use description
- Risk management file (per JIS T 14971 / ISO 14971:2019)
- Clinical evaluation and performance testing data
- Labeling and Instructions for Use (IFU) in Japanese
- Quality Management System (QMS) documentation
- Usability engineering file (UEF) including:
- Use specification: Who will use the device, where, and for what purpose
- Use-related risk analysis (URRA): User tasks, potential use errors, harms, hazard-related use scenarios, risk control
- Formative evaluation summaries: Iterative testing results and design improvements
- Summative evaluation report: Final validation demonstrating safe and effective use
4. What Global Manufacturers Should Know About Usability Engineering in Japan
Rational Justification
Many global manufacturers with experience in FDA submissions or EU MDR compliance already conduct usability testing as a standard part of development. The good news is that existing HFE/UE work can often be adapted for PMDA submissions. However, to use foreign HFE data, manufacturers must provide a rational justification for two key points:
- Equivalence of Use Context: Must prove that the intended users, use environments, and use scenarios in the foreign study are essentially equivalent to those in Japan.
- Localization Risk Assessment: Must demonstrate that Japanese-specific elements; such as language displays, unit notations (e.g., specific medical units), and localized labeling do not introduce new risks or use errors.
Integration with Risk Management
In addition to the providing rationale for the above, usability engineering file must clearly link to your risk management file (per JIS T 14971). PMDA reviewers expect to see:
- Traceability: Use-related hazards identified in risk analysis must be addressed in summative testing
- Outcome-Based Evaluation: Summative evaluation is viewed as a confirmation of risk control effectiveness. Reviewers dislike conclusory statements like “safety was confirmed”; instead, documentation should state that the evaluation confirmed the design-based risk controls are effective for the identified hazard-related scenarios.
Cases Requiring In-Country Studies
Additional studies in Japan may be necessary for:
- Patient-facing Software as a Medical Device (SaMD): Software intended for use by patients rather than healthcare professionals.
- High-impact display results: Devices where the results shown on the display directly impact diagnostic or treatment decisions.
- UI misinterpretation risks: Any case where the Japanese-language User Interface (UI) might pose a risk of misinterpretation or lead to new use errors.
Why is it important?
Testing with Japanese users ensures that language, cultural context, and demographic factors are properly accounted for and may reveal use errors that wouldn’t surface in other testing environments abroad.
5. How We Can Help
At Uism, we specialize in helping international manufacturers navigate the Japanese regulatory landscape for medical device usability. Our services include:
Local Usability Testing
- Planning and executing formative and summative usability studies with Japanese users
- Recruiting hard-to-reach participants such as clinicians, elderly users, or patients with specific conditions
- Testing in simulated environments that reflect actual use conditions in Japan
Regulatory-Ready Documentation
- Structuring studies and reports to align with PMDA expectations and JIS T 62366-1 requirements
- Developing usability engineering documents
- Supporting task analyses, URRA
- Formative/summative evaluation reports
Localization Support
- Evaluating Japanese-language IFU, labeling, and on-screen interfaces
- Identifying cultural or workflow-specific issues that may affect usability
- Supporting UI/UX refinements for the Japanese market
Bilingual Expertise
- Providing bilingual researchers for seamless communication with global teams
While we do not directly manage regulatory submissions, our research provides the evidence and documentation you need to support your PMDA filing strategy.
As a member of the ReSight Global, which includes leading human factors firms such as Bold Insight in the U.S. and uintent in Germany, we bring not only local execution capabilities in Japan, but also shared expertise and best practices from some of the most experienced teams in the world. This global collaboration ensures our approach is consistent, rigorous, and informed by the latest regulatory trends.
Conclusion
Japan’s medical device market is evolving rapidly. While HFE/UE resources and regulatory precedents remain more limited compared to the US or EU, usability is increasingly recognized as a critical element of medical device safety and effectiveness.
For international manufacturers, the April 2024 enforcement of JIS T 62366-1:2022 means usability engineering is no longer optional. Whether you’re adapting existing HFE/UE work for Japan or starting from scratch, testing with Japanese users and documenting use-related risks in a way that aligns with PMDA expectations is now essential.
Uism is here to help. We offer end-to-end support for planning, executing, and documenting usability testing in Japan, bridging the gap between global standards and local regulatory requirements.
Let’s connect and explore how we can support your human factors strategy in Japan.
