Glossary
Terms from maintenance and field service, in plain words.
- AssetA physical item of equipment that a business owns, operates, and maintains.
- Asset hierarchyA parent-child structure that organizes assets by location, system, or function, from site down to component.
- AvailabilityAvailability is the share of required time in which a machine can work. EN 13306 offers three time ratios, and each leaves out different stops, so state which one you use.
- Computerized maintenance management system (CMMS)Software that plans, schedules, and records maintenance work and the assets it is done on.
- Condition-based maintenanceMaintenance triggered by the measured condition of an asset rather than by a fixed schedule.
- Corrective maintenanceMaintenance done after a fault is found, to restore an asset to working condition.
- DowntimeThe time during which an asset or production line is not available for use.
- Enterprise asset management (EAM)The management of physical assets across their whole life, from acquisition to disposal, and the software that supports it.
- Field service management (FSM)The scheduling, dispatching, and recording of work done at customer sites, and the software that supports it.
- First-time fix rateThe share of service jobs resolved on the first visit, without a return trip.
- Lockout/tagout (LOTO)A safety procedure that isolates and locks energy sources so equipment cannot start during maintenance.
- Maintenance backlogMaintenance work that has been identified and approved but not yet completed.
- Mean time between failures (MTBF)MTBF is the average operating time between two failures of a repairable machine: operating hours divided by the number of failures. It does not tell you when the next failure comes.
- Mean time to repair (MTTR)MTTR is the average time a machine is stopped per failure, from the failure until it runs again. EN 13306 counts the waiting; the hands-on part is mean repair time (MRT).
- Overall equipment effectiveness (OEE)OEE is availability times performance times quality. It tells you what share of planned production time a machine spends making good parts at its ideal speed.
- Predictive maintenancePredictive maintenance is condition-based maintenance that starts because a forecast shows wear. An alarm at a fixed limit is not enough: the forecast needs repeated readings, a trend, and a limit.
- Preventive maintenanceMaintenance done before a failure to lower its chance. In daily use it means fixed intervals; EN 13306 also counts condition-based and predictive work.
- Root cause analysisA structured method for finding the underlying cause of a failure so it does not recur.
- Service level agreement (SLA)An agreement that sets the service a provider commits to, such as response and resolution times.
- Spare partsComponents kept in stock to replace worn or failed parts during maintenance and repair.
- Work orderA document that authorizes a maintenance or service task and records who did what, when, and with which parts.