Definition
Non-Functional Requirements are those that are necessary to support the provision of the Functional Requirements.
Examples
A system may be required to present the user with a real-time display of the number of records in a database. This is a functional requirement. In order to fulfill this requirement, the system architects must ensure that the database is capable of updating its record count within a predetermined response time - this is a non-functional requirement.
Sufficient network bandwidth may also be a non-functional requirement of a system.
Other examples:
- Security
- Response time / Performance
- Safety
- Availability (see Service Level Agreement)
See also
- -ilities (like accessibility, reliability, usability, etc.)
- Functional Requirements
- Usability Requirements
- Non-Functional Requirements framework (NFR)