Nicht-funktionale Anforderungen (NFRs) sind entscheidende Aspekte von Systemdesign that define how a system performs under various conditions, rather than what the system does. These requirements encompass a wide range of attributes, including usability, reliability, performance, security, and compliance with standards. Unlike functional requirements, which specify the specific functions or features of a system, NFRs focus on the quality and constraints of those functions.
Zum Beispiel könnte eine funktionale Anforderung state that a user must be able to log in to a system, while a corresponding NFR could specify that the login process must occur within two seconds and must not exceed three failed attempts for security reasons. Other common NFRs include:
- Leistung: Wie schnell ein System auf Benutzereingaben reagiert oder Daten verarbeitet.
- Skalierbarkeit: The ability to handle growth in users or data volume without performance degradation.
- Sicherheit: Measures and protocols zum Schutz von Daten und zur Wahrung der Privatsphäre der Nutzer.
- Benutzerfreundlichkeit: Wie einfach und intuitiv das System für die Nutzer ist.
- Zuverlässigkeit: The system’s ability to operate consistently over time ohne Ausfälle zu funktionieren.
Das Verstehen und Festlegen von NFRs ist während des Softwareentwicklung lifecycle, as they can significantly impact user satisfaction and system success. They also play a crucial role in testing and validation processes, ensuring that a system not only meets its functional requirements but also provides a satisfactory user experience and complies with necessary standards and regulations.