ISO 9241-171:2008

Overview

ISO 9241-171:2008 - Ergonomics of human-system interaction: Guidance on software accessibility provides practical ergonomics guidance and specifications for designing accessible software used at work, home, education and in public places. The standard focuses on maximizing accessibility and usability across the widest range of physical, sensory and cognitive abilities (including temporary disabilities and older users). It applies to interactive systems and a broad range of software (office, web, learning support, library systems) and promotes integration with assistive technologies rather than defining assistive-technology behavior.

Key topics and technical requirements

ISO 9241-171 structures guidance around practical software accessibility concerns. Key technical topics include:

• General principles: Human-centred design, individualization, context-based design and early incorporation of accessibility goals to improve usability and reduce retrofit costs.
• User-interface elements: Names, labels and consistent labelling of controls to support navigation and assistive tools.
• User preference settings & adjustments: Mechanisms for customization (display, input, audio) to meet diverse needs.
• Compatibility with assistive technologies: Requirements for platforms and applications to integrate with screen readers, magnifiers, on‑screen keyboards and other assistive software/hardware.
• Inputs: Alternative input options, keyboard focus and keyboard input support, and pointing-device considerations.
• Outputs: Visual output (displays, text/fonts, colour, windows), audio output and text equivalents (captions), media and tactile output.
• Closed systems & support: Considerations when systems restrict third‑party assistive tools; online documentation, “Help” and support-service accessibility.
• Assessment and conformance: Annexes include a list of requirements and a sample procedure for assessing applicability and conformance.

Practical applications

ISO 9241-171 is used to:

• Inform accessible user-interface design and development practices for desktop, web and embedded interactive systems.
• Define procurement requirements and contracts to ensure accessible software platforms and applications.
• Guide usability and accessibility evaluations, testing and conformance assessments.
• Shape integration strategies for assistive technologies and platform-level accessibility APIs.
• Support organizational accessibility policies, inclusive design programs and compliance with legal accessibility obligations.

Who should use it

• User-interface designers and UX professionals
• Software developers and platform architects
• Product managers and procurement officers
• Accessibility specialists, evaluators and testers
• Technical writers and support/service teams

Related standards

ISO 9241-171 complements other standards and guidance such as ISO 9241-110, ISO 9241 series (parts 11–17), ISO 13407, ISO 14915, and web-specific guidance like WCAG for Web content accessibility.

Keywords: ISO 9241-171, software accessibility, ergonomics, human-system interaction, accessibility guidelines, assistive technologies, usability, inclusive design, accessibility standards.