Glossary · Automation fundamentals, platforms and components
Usability
Also known as: Ease of use
German: Usability
According to ISO 9241-11, usability is the extent to which a system, product or service can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.
- Automation components
- Standards
- Technical documentation
In one sentence
Usability is how effectively, efficiently and satisfactorily specified users reach their goals with a product in a given context (ISO 9241-11).
Example
A usability test shows that operators take 40 seconds to find the fault acknowledgment on the new HMI, so the button is moved to the alarm banner.
Explained in context
Context cards connect this term with others to answer one question. Also in British English and German.
- Cognitive load and split attention: why figures, labels and text belong togetherTransitional topicWhat does cognitive load theory say about combining figures and text in instructions, and what follows for technical documentation?UKDeutsch
- Cognitive psychology in technical communication: theory, application and the bridges between themTransitional topicWhat is the difference between cognitive psychology as theory and its application in documentation, and how do the two fit together?UKDeutsch
- Working memory and procedure steps: why "seven plus or minus two" is the wrong ruleTransitional topicDoes working memory research justify a fixed maximum number of steps in a procedure, such as seven plus or minus two?UKDeutsch
- Task analysis: one task, three lensesIs task analysis one method, or are technical, collaborative and cognitive task analysis different things?UKDeutsch
How it applies
- Engineering: HMI design, operator panels and service access benefit from usability methods: user research, prototypes and tests with real operators. Poor usability increases Human error and workarounds.
- Safety: Usability problems can lead to Reasonably foreseeable misuse, which the risk assessment must consider. In medical devices, usability engineering is formalized in IEC 62366-1.
- Documentation: Instructions are part of the product's usability. Test manuals and HMI help texts with users, and apply the criteria of Safety information usability to warnings. Plan usability tests early, when changes are still cheap.
Usability vs. user experience
Usability focuses on effectiveness, efficiency and satisfaction in using a product. User experience (UX) is broader and includes perceptions and responses before, during and after use.