MTBF (Mean Time Between Failures)
MTBF is the average operating time between failures of a repairable asset. A higher MTBF means a more reliable machine. It is a core reliability metric used to compare assets, target maintenance and justify predictive-maintenance investment.
MTBF applies to assets that are repaired and returned to service, distinguishing it from mean time to failure for non-repairable items. It is a headline reliability metric used to compare equipment, plan spares and set maintenance intervals, but it must be read carefully: an average hides the failure distribution, so two machines with the same MTBF can behave very differently. It is most meaningful within the constant-failure-rate phase of an asset's life.
Related reading
- Predictive maintenance: a practical guide
- Fiix (Rockwell Automation)
- IBM Maximo Application Suite
- Bathtub Curve
- Unplanned Downtime
- MTTR (Mean Time To Repair)
Related terms
Bathtub Curve · Unplanned Downtime · MTTR (Mean Time To Repair) · Predictive Maintenance (PdM) · RCM (Reliability-Centred Maintenance) · Weibull Analysis · Asset Performance Management (APM)
Related guides
Software
Fiix (Rockwell Automation)
Cloud CMMS with an AI assistant, now part of Rockwell.
IBM Maximo Application Suite
Enterprise asset management with built-in monitoring and AI.
Where this applies
Establishing a lubrication management programme · Establishing a precision alignment and balancing programme · Running a bearing reliability programme · Establishing a laser shaft alignment programme