Usability engineering is closely related to risk management. The following video, which is a part of our online course on Usability engineering and IEC 62366-1 deals with this topic in-depth. You can register on the course or read more about it by following the link.

What is risk in usability engineering?

Before talking about the relationship between usability engineering and risk management, a couple of definitions are in order. ISO 14971, the risk management standard, defines safety as

“freedom from unacceptable risk.”
ISO 14971:2019, 3.26

In terms of usability engineering and the IEC 62366-1 standard, the first and foremost rule is that the interface must be safe and not introduce any unacceptable risks. Risk is defined as:

“the combination of probability of occurrence of harm and the severity of that harm”
ISO 14971:2019, 3.18

Risk according to ISO 14971

The goal is to design the user interface so that the probability of occurrence of harm and/or the severity the harm is reduced to an acceptable level or as far as possible.

When referring to risk in conjunction with usability engineering, it is important to distinguish between risk in this context (product safety risk) and e.g. corporate risk management, or project risk. Also, risk in usability engineering includes risk to users, patients, or third parties, which means anyone who is in the vicinity of the medical device in question.


What is the user interface?

User interface is defined as:

“means by which the USER and the MEDICAL DEVICE interact”
IEC 62366-1:2016, 3.26

The user interface comprises much more than what people in general think of when hearing the term user interface. It includes:

  • The physically accessible parts of the device that the user would interact with
  • Auditory signals
  • Visual signals
  • Tactile displays, and
  • Accompanying documentation (including instructions for use)

The purpose of usability engineering

Usability engineers are likely to describe usability engineering as a process that helps in designing great products, but from a regulatory body’s point-of-view, the same process is used, but the scope is limited to usability engineering as it relates to safety.


Safety in risk management vs. safety in usability engineering

Medical device risk management is about achieving a safe medical device. Medical device risks can stem from many different areas, such as:

  • Design flaws
  • Production failures,
  • Electrical issues, and
  • The correct or incorrect use of a medical device

Risk controls that aim to reduce the risks in various areas are implemented primarily in the design and production process.

Risks relating to the user interface are usually controlled in the design, labelling or the training on the product.

ISO 14791 is the overall risk management standard for medical devices, but it is not the only standard that concerns risk, medical devices and usability engineering. There are:

  • Product standards that include primary operating functions of various types of medical devices
  • The IEC 60601-1 and its collateral IEC 60601-1-6 on usability engineering
  • The IEC 62366-1 standard

The IEC 62366-1 is a process standard that establishes the requirements of how usability engineering work should be conducted. In other words, it is similar to ISO 14971, only with a narrower scope that only relates to the user interface.

IEC 62366-1 and ISO 14971

The close connection between risk management according to ISO 14971 and usability engineering according to IEC 62366-1 is confirmed by a flowchart that can be found in the IEC 62366-1 standard. A simplified version of the flowchart is depicted below.

The connection between usability engineering and risk management

Usability engineering goals

The usability engineer’s job is to ensure that the device will be safe and have as low risk as possible with regards to the user interface. This is the regulatory requirement and perspective, but it may be equally important to achieve a good user experience, particularly if the safety depends on the user being able to use the device at all. And there are many reasons to design the user interface to not only be safe, but also to provide a good user experience that goes beyond safety.

In conclusion, usability engineering and risk management are connected in many ways, and all steps should be taken to ensure safe and user-friendly medical devices.

Would you like to learn more about Usability Engineering?

Get instant access to our online Usability Engineering and IEC 62366-1 course right here. In 8 hours, you can learn how to establish a pragmatic usability engineering process that enables regulatory clearance and great product design during this self-paced, interactive online course.

This course is taken by anyone working in product management, such as R&D and QA engineers, product and application specialists, and product owners.

Michaela Kauer Franz

Michaela Kauer-Franz

Dr. Michaela Kauer-Franz is a highly esteemed trainer, consultant, and entrepreneur in the medical device industry. She has vast hands-on experience, having developed, amongst other things, monitoring devices for ICU and NICUs, diabetes care products, and women’s health products.

Michaela Kauer-Franz has received numerous awards including the Red Dot Winner Interface Design Award and being nominated for the UX Design Award. She is a lecturer for the design of medical and critical user interfaces at the Technische Universität Darmstadt and part of the national standardization committees in Germany for Usability and User Experience.