Definition:
MTBF is the predicted elapsed operating time between failures of a repairable system during normal operation.
Key Points:
- Primarily a measure of availability.
- Not directly equivalent to SIL requirements without considering failure modes.
Example:
A valve stem packing on a valve, which is repairable, has an MTBF of 5,000 hours.
See Also: MTTF
Cited Source:
- IEC 61709:2017
- Limble article – Guide to Understanding Failure Metrics