How to get started - Establish a Human Factors Design Process For Medical Devices?
When it comes to human factors design, the process generally boils down to three main parts:
User research
User evaluation
User validation
Every product plan will look a little different depending on your starting point—whether you’re building a brand-new software product or updating something that’s already out in the world.
As you go through each research and testing phase, here are some important things to cover in your plan:
The physical product interface
The software UI – Is it intuitive?
Does it work the way users expect it to?User manuals and quick-start guides – Do they explain everything clearly and in a way that's easy to follow?
Labeling – Is it simple, readable, and user-friendly?
Training and training materials – What kind of training will users need, and how will it be delivered?
Here are the 10 main deliverables you’ll need to include:
Use specification
User interface features related to safety and how you've worked to minimize use errors
Known hazards or risky situations
Hazard-related use scenarios
Hazard-related use scenarios specifically for summative testing
User interface specification
User interface evaluation plan
Formative usability test reports
Summative usability test report
Usability engineering report
It’s a good idea to bake your human factors process into your overall quality management system early on—and keep it flexible. Treat it like a living document that evolves as your product does. That way, everyone on your team stays in the loop, and it’s easier to make updates when needed.
Will I have to Think About Human Factors for Medical Device Labeling?
In short, yes. Labeling is just as much a part of the user interface as the buttons on your device or the app that goes with it. This includes things like:
Instructions for use
User manuals
Quick-start guides
Packaging
The FDA makes it pretty clear: if there’s a use-related risk, the first thing you should try to fix is the device design—not just rely on labeling or training. Why? Because:
Changing the design is usually more effective than tweaking the labeling or relying on training. Labeling might not be around when someone needs it, and training depends on memory—which isn’t always reliable.
Another thing the FDA looks for is whether your labeling covers “reasonably foreseeable” misuse. That means if something could realistically go wrong—even if it’s not how the product is meant to be used—you should include a warning.
For example, if your device is meant to be used at home, there’s a good chance it could end up within reach of kids. That’s the kind of thing you’d want to call out in your labeling, along with what the risk is and what could happen.
How Do You Fit Human Factors Usability Testing into Product Development?
The best way to make sure usability testing doesn’t get left behind during product development is to build user research and evaluation into every stage of the process. There’s no one-size-fits-all approach—so it’s worth thinking about your device and what kind of testing will actually give you the most helpful insights. Some common methods include:
Watching users interact with the product (user observation)
Running interviews—either one-on-one or in groups
Doing benchmark tests to compare usability across versions or against competitors
When it comes to human factors validation, both the FDA and IEC 62366 offer solid guidance. The FDA is a bit more specific, though—they expect manufacturers to test with at least 15 U.S. participants, and those tests should happen in a real-world environment, not just a lab setting.
If you’re not sure what kind of validation makes sense for your product, a good trick is to look up summaries of regulatory submissions for similar devices. These often include a high-level overview of the usability testing that was done.
And don’t forget—you can always send the FDA a draft of your human factors plan and ask for their input. They’re usually pretty open to reviewing it early on.
