Iso 9241-11 Usability Definition 2018 Jun 2026

A major criticism of the 1998 version was that it felt separate from accessibility standards (like WCAG). The 2018 revision explicitly integrates accessibility. It frames accessibility not as a checklist for compliance, but as the result of designing for the widest possible range of users.

Many organizations previously equated usability with speed. The 2018 standard explicitly requires (effectiveness, efficiency, satisfaction) to be reported. iso 9241-11 usability definition 2018

| Domain | Example usability claim (per ISO 9241-11:2018) | |--------|------------------------------------------------| | | For frequent shoppers using a mobile phone in a commute context, the checkout process achieves 100% effectiveness, average 45 seconds per checkout, and 90% positive satisfaction ratings. | | Medical device (infusion pump) | For hospital nurses under time pressure (simulated ICU), the pump achieves zero critical errors, task completion within 60 sec, and no reported frustration. | | Self-service kiosk | For elderly first-time users in a bright airport hall, ticket purchase achieves 95% success, average 2 min, and post-task rating ≥ 8/10. | A major criticism of the 1998 version was

| Aspect | 1998 Version | 2018 Version | |--------|--------------|----------------| | | Focused on product’s “ease of use” | Focused on outcomes of use in a specific context | | Satisfaction | Vaguely defined | Clarified: freedom from discomfort and positive attitudes | | Context | Implied | Explicitly required for any usability claim | | Applicability | Primarily software interfaces | All products, systems, services (physical, digital, mixed) | | Measurement | Brief examples | More detailed guidance on measurement methods (including subjective, objective, and performance metrics) | Many organizations previously equated usability with speed

redefines usability as a contextual, measurable outcome composed of effectiveness, efficiency, and satisfaction. This modern definition aligns with current user experience practice and service design, moving beyond software-only “ease of use.” For organizations, adopting the 2018 definition means: