MTBF (Mean Time Between Failures) is a reliability indicator that measures the average operating time of a repairable piece of equipment between two successive failures. It is computed by dividing the total operating time by the number of failures that occurred over a given period. Expressed in hours (or days), a high MTBF reflects reliable equipment that rarely breaks down.
MTBF should not be confused with MTTF (Mean Time To Failure), reserved for non-repairable components that are replaced rather than repaired. MTBF is always read alongside MTTR (mean time to repair): combined, these two indicators determine an asset's availability rate, following the formula availability = MTBF / (MTBF + MTTR). A piece of equipment can show a good MTBF yet remain poorly available if its repairs take a long time.
In industrial maintenance, MTBF is used to plan preventive maintenance, prioritize critical equipment and put service contracts on an objective footing. It is one of the reference KPIs of a CMMS, alongside the failure rate or the reliability target set in an SLA. Tracking it regularly makes it possible to detect a reliability drift before it turns into costly production downtime.
In eyeot, this indicator fits within the logic of the Maintenance module, which consolidates the history of work orders and failures per piece of equipment.