Non-Functional Requirements describe the quality attributes of a system rather than specific functionalities. They encompass performance, usability, reliability, security and other characteristics that affect user experience.
Key Categories of Non-Functional Requirements:
- Performance: Response times, throughput and resource usage.
- Usability: User interface design, accessibility and user satisfaction.
- Reliability: System availability, fault tolerance and recovery processes.
- Security: Data protection measures, authentication and authorisation protocols.
Non-functional requirements are critical for ensuring that a system meets user expectations beyond basic functionality.