Amendment 1 (2020-06) to the IEC 62366-1 standard for Usability Engineering published

The international standard IEC 62366-1:2015 Medical devices — Part 1: Application of usability engineering (UE) to medical devices has been amended. A consolidated version (edition 1.1) is available as a so-called redline version. The changes presented in the Amendment 1 (A1) do not changes the process of UE. They are merely a further strengthening of the link with risk management as defined by ISO 14971:2019. As a result of this alignment, edition 1.1 of IEC 62366-1 should be used in conjunction with ISO 14971:2019.

In this blog the key changes that will affect UE as well as the relation with ISO 14971:2019 are discussed.

IEC 62366-1 and ISO 14971

Recently the ISO 14971 is updated (2019) and the scope of both standard is clearly illustrates, briefly:

  • The scope of ISO 14971 already included reasonably foreseeable use, i.e. all types of use including reasonably foreseeable misuse. This definition is newly added to updated version of ISO 14971, and is defined as (§3.15):
    Use of a product or system in a way not intended by the manufacturer, but which can result from readily predictable human behaviour
    The definition also includes 2 notes to further clarify:
    • Readily predictable human behaviour includes the behaviour of all types of users, e.g. lay and professional users
    • Reasonably foreseeable misuse can be intentional or unintentional.
  • The scope of IEC 62366-1 covers Normal use, i.e. Correct Use and Use Error. The term reasonably foreseeable misuse is not defined in the IEC 62366-1, for that definition it refers to ISO14971, but it does provide examples and introduces the following diagram to illustrate the concept.

  • Clearly illustrated here is that the scope of ISO 14971 includes the full scope of IEC 62366-1.
  • ISO 14971:2019 requires postproduction information that needs to be collected should also focus on the usability device that should feed into the usability engineering process. A1 of IEC 62366-1 now also includes some more guidance on how to use postproduction information in the UE process.


Definition 3.2: Accompanying documents: it now explicitly includes information for decommissioning and disposal to support safe use.

Definition 3.11: Primary operating functions: the definition has not changed, but in the Annex A guidance, the statement is made that IEC 62366-1 does not require identification of primary operating functions, but only focus on the description and evaluation of hazard related use scenarios. However primary operating functions identified in some product-specific standards might be related to tasks of hazard related use scenarios.

Definition 3.22: Use scenario: In the Annex A guidance, the introduction of the term “critical task” is made, with reference to and in alignment with FDA use of the term “critical task” found in US FDA, (2016), Guidance for Industry and Food and Drug Administration Staff: Applying Human Factors and Usability Engineering to Medical Devices, February 3, 2016 and US FDA, (2016), Draft Guidance for Industry and FDA Staff: Combination Product Design and Development, February 2). Note that this term has not been included in IEC 62366-1’s formal list of definitions.

Definition 3.25: User group: The definition has changed to stress that user groups are subsets of users who are differentiated by “factors that are likely to influence their interactions with the medical device.” In the note some attributes of distinct users groups are given: expertise (lay versus professional user) age (child versus elderly persons).


  • Risk control measures (section 4.1.2): is now fully aligned with ISO 14971, by including ‘manufacture’ in the first option for risk control and including ‘training to users’ in the third option for risk control.

Usability Engineering process:

  • Planning for Summative evaluation (section 5.7.3): new requirements for usability test are introduced:
    • Justify how the characteristics of the test participants are representative of the intended user profiles;
    • justifying how the test participants are grouped into distinct user groups for the purpose of determining the number of test participants;
    • rationalize how the test environment and conditions of use are representative of the intended use environment;
    • Define correct use for each hazard-related use scenario. In subclause 5.7.3 Summative evaluation planning the requirement to apply the formal acceptance criteria that the manufacturer has defined for risk acceptability are removed from the standard. Instead there needs to be an assessment of whether use errors occurred during tests. Performing task of a hazard related use scenario without “difficulty or struggle” and “close calls” are markers for Correct use.
    • Ensure there is feedback from post production information collected and that this is fed back into the usability engineering and risk management process.

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Ra'na Saleem
Post date: November 12, 2020
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