The mean average operating time between consecutive system failures in a repairable software system is measured by:
AMean Time To Repair (MTTR)
BMean Time To Failure (MTTF)
CFailure Rate ($lambda$)
DMean Time Between Failures (MTBF)
Explanation
MTBF calculates operational uptime reliability between repair cycles ($MTBF = MTTF + MTTR$).
Exam Relevance
- Topic: Software Quality Metrics
- Subtopic: Reliability Metrics

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