Human Factors Engineering vs. UX: Are They Really All That Different?

 In Design Strategy, Human Factors & Usability Testing, Medical Product Design

From a medical device development perspective, the goal of human factors engineering, usability, and user experience activities is the same: To release a product that meets users’ needs in a safe, effective, straightforward, and delightful way.

But the technical definitions of these terms can vary. As a result, the terms are often perceived as being markedly different — to the detriment of medical device developers like you.

The best case scenario is that this misperception causes confusion. And the worst case scenario? You develop a product that falls short in one of two ways:

  1. It doesn’t meet users’ standards and tastes because you’re too focused on the technology and the FDA hurdles, or

  2. It doesn’t meet the FDA’s guidance because you’re too focused on the user experience and aesthetic design.

To avoid both of these scenarios, stop getting caught up in the terminology. Instead, employ a robust development process that aims to deliver a superior user experience as your number one objective while at the same time meeting the FDA’s guidelines and IEC standards.

Defining Human Factors Engineering, Usability, and User Experience in the Medical Device Industry

Before we discuss strategies to get out of the terminology weeds to create a user-centric product, it’s helpful to define the terms at hand:

Human Factors Engineering

The 2016 FDA human factors guidance defines human factors engineering (often shortened to HFE) as:

The application of knowledge about human behavior, abilities, limitations, and other characteristics of medical device users to the design of medical devices including mechanical and software driven user interfaces, systems, tasks, user documentation, and user training to enhance and demonstrate safe and effective use.

In simpler terms, HFE focuses on how the end user (the human) can access a product’s capabilities (factors) safely and effectively.

Also note that the FDA recognizes IEC 62366-1 as the prevailing international standard that should guide HFE efforts for medical device R&D teams.

Usability and Usability Engineering

Usability (aka usability engineering or UE) is exactly the same as HFE. HFE is simply the term the United States uses, while Europe and most other countries refer to it as UE.

Even the FDA concedes, “Human factors engineering and usability engineering can be considered to be synonymous.”

User Experience

User experience (UX) refers to the end user’s experience with a product. UX is a broader, catch-all term and is widely used beyond the medical device industry. The Nielsen Norman Group states that “user experience encompasses all aspects of the end-user’s interaction with the company, its services, and its products.”

For our purposes, according to one of the general ISO definitions, UX includes all users’ emotions, beliefs, preferences, perceptions, physical and psychological responses, behaviors and accomplishments that occur before, during, and after use. Moreover, UX is made up of many different aspects of a product, including usability and safety as well as value and desirability.

High-quality UX considers additional factors like desirability, brand perception, and total value to both the business and users. It can also extend across a whole product or service ecosystem.

In a sense, usability nests under the much broader UX umbrella since — at an absolute minimum — a user requires sufficient usability to accomplish a task.

Notes on User Experience Design

It’s important to understand that the term “user experience” is not equivalent to user experience design (UX design or UxD). UxD is the discipline leveraged to create products that provide a positive and valuable UX.

Like HFE/UE, UxD is a process that focuses on the end user but with a slightly different application of the knowledge. In all cases, you’re designing products that are usable, useful, and delightful to interact with.

Moreover, HFE/UE and UxD use similar information in slightly different ways. While both use information to ensure usable and useful products, as mentioned, HFE/UE focuses this knowledge ”to enhance and demonstrate safe and effective use.” Meanwhile, UxD opens up this application of knowledge to fuel a total perception of value.

Remember: Both disciplines (HFE/UE and UxD) ultimately strive toward a positive and valuable UX.

Why Medical Device Companies Neglect UX

The FDA asks that medical devices adhere to the guidance outlined in their own document as well as in IEC 62366-1. The IEC document emphasizes safe use and risk mitigation of the user interface(s) by prioritizing HFE/UE processes.

Furthermore, the FDA mandates safe and effective use. Specifically, IEC 62366-2 describes how medical device development teams should identify user tasks and experiences. As discussed, user experiences are inextricably linked to user feelings and opinions. That’s why, however indirectly, the FDA’s use of the word “effective” refers to the product’s usability and its resulting UX.

In sum, the IEC and the FDA do concern themselves with UX. Still, industry experts have come to realize that these regulatory documents are in fact using “effectiveness” to signify UX.

So why is it that so many companies neglect UX despite the guidance?

It could be because, as mentioned, the definition of effectiveness and its connection to UX isn’t clear. More often, UX just isn’t seen as a “must have” to these companies. There’s also an overall lack of HFE/UE processes in place at these companies because of a lack of understanding and/or resources.

The first step of development is making sure the product does what users need it to do. A lot of companies stop there — at the bare minimum based on the FDA guidance. But true UX, which is implied through the processes that the FDA/IEC documents lay out, goes above and beyond this bare minimum.

Why Neglecting UX Doesn’t Work

Pleasing the user isn’t typically top priority for engineering teams in the medical device industry. Again, they lack proper understanding of the FDA’s requirements, usually because of a lack of resources despite their best efforts.

But beware: The medical device industry is an increasingly competitive space. It’s no longer enough to differentiate your product based on its technology alone. Another company will come along with that same technology — and a better UX that includes superior graphic design and visual aesthetics, too.

What’s more, the COVID-19 pandemic has accelerated the popularity of home health products. Regular, everyday users in their homes expect an even easier, more pleasant experience than an experienced doctor or nurse in a hospital setting. It’s only a matter of time before this trend informs UX expectations — and demands — for non-home health medical devices in an even bigger way.

The most compelling reason to look beyond the bare minimum toward a better UX? A medical device that is safe should be table stakes.

Think of it this way: If you were looking to buy a new hair dryer, you’d assume that anything on the market wouldn’t electrocute you. Again, product safety is the expectation. Instead, you’d make your purchasing decisions on differentiating qualities including ease of use.

Neglecting Your Regulatory Duties Doesn’t Work Either

Although it’s arguably less common, it’s also possible to focus too much on UX.

If you concern yourself with pleasing users above all else, you may miss important FDA guidance and, as a result, your device might not gain approval.

No medical device company wants to re-work their product and re-seek FDA acceptance. It’s extremely costly to backtrack in your development process, to say the least.

So how do you mitigate these two, equally important facets of medical device design to ensure your product is not only approved but provides its end users with a first-rate experience?

3 Tips for Navigating Your Medical Device’s Usability and UX Journey

The key to creating a medical device that checks the right regulatory boxes and meets users’ increasingly demanding expectations is finding the right balance between the technical and UX aspects of development.

1. Use This Overlooked IEC Standard as Your Guide to a User-Friendly Medical Device

IEC 62366-1 is followed by a related but separate document: IEC 62366-2. It’s titled Technical Report Part 2: Guidance on the application of usability engineering to medical devices. We briefly mentioned it above.

The standard states “it also helps manufacturers produce medical devices that have well designed user interfaces that satisfy users. As such, it can propel a manufacturer beyond a common sense approach to user interface design to an approach that fully embraces usability engineering as an essential step toward design excellence.”

It’s not enough to do the minimum to satisfy the FDA and hope a superb UX will follow. Instead, review this guidance in the early stages of development. We’d wager to say it’s an even better, more holistic guide than IEC 62366-1.

2. Plan and Time Your Human Factors Activities Right

To create a successful product, you need to have a strong focus on usability during two phases of development:

  1. At the beginning while creating requirements, before your product is designed, and

  2. During the design process.

At the beginning of your development process, you must clearly define user needs and understand the problem you’re trying to solve for your prospective customers. A robust HFE plan is non-negotiable. It ensures that the proper process, resources, and funding are in place for the duration of the project.

Focusing on usability during your design process is arguably even more important. The user needs will begin to manifest into conceptual solutions and design concepts. This phase will include many cycles of design and build — with ever-important formative evaluations. The cyclical nature of this portion of development is vital. It establishes the connection between your technology and the end user.

The takeaway? Don’t wait to incorporate usability into your medical device development process. After all, summative usability testing is the time to confirm that your product is safe and effective, not the time to react to user feedback and make changes.

3. Trade Your Tech-Driven Culture for a User-Centered Design Philosophy

The R&D department is typically run by a chief technology officer and/or an engineering VP — very technically minded individuals.

Of course, you have human factors and marketing professionals on your team, too. But they’re often working beside or under your R&D leaders. Meaning all decisions are driven by R&D and, therefore, inherently tech-focused.

What does this mean? Your company may need a cultural shift.

If your culture considers usability a mere regulatory box to check, you’ll need to work to include broader UX in that definition or you may never design a truly user-centric medical device that can compete in today’s market.

HFE and UX Exist to Provide a Quality User Experience

HFE, UE, UX, UxD — these terms and their definitions matter. But don’t forget that, ultimately, HFE and UxD both aim to create medical devices with exceptional UX.

Focus on delivering that exceptional user experience to everyone who interacts with your medical device. By doing so, you’ll create loyal customers who not only commit to that single product but to your brand as a whole.


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