MTTR (Mean Time To Repair) measures the average time needed to bring a piece of equipment back into service after a failure. It is computed by dividing the total time spent on repairs by the number of interventions carried out over a period. It is the maintainability indicator par excellence: the lower the MTTR, the more the equipment (and the organization that maintains it) is able to repair quickly.
The scope of MTTR varies from one organization to another: it may cover only the actual repair time, or include diagnosis, waiting for spare parts and restart testing. Defining this scope clearly is essential in order to compare values across sites or providers. In IT and ITSM, the acronym is sometimes read as Mean Time To Restore/Recovery, with a similar logic applied to the restoration of a service.
MTTR is read as a complement to MTBF (mean time between failures): together, they determine an asset's availability rate following the formula availability = MTBF / (MTBF + MTTR). It is also a frequent commitment in service contracts, where an SLA sets a maximum restoration time.
Within eyeot, MTTR falls under the Maintenance module, which records the duration of interventions per piece of equipment and per technician.