next previous contents
Next: Usability Up: Quality characteristics and subcharacteristics Previous: Functionality


A set of attributes that bear on the capability of software to maintain its level of performance under stated conditions for a stated period of time. (ISO 9126: 1991, 4.2)

NOTE -- Wear or ageing does not occur in software. Limitations in reliability are due to faults in requirements, design and implementation. Failures due to these faults depend on the way the software product is used and the program options selected rather than on elapsed time. (ISO 9126: 1991, 4.2)