file MV-GLOSSARY
Maintenance glossary
The terms of industrial maintenance and CMMS, defined simply. Each definition links to a fuller guide.
- 01Availability rate
- The availability rate expresses the share of time during which an asset is able to operate compared with the total required time. It is often derived from the ratio of uptime to the sum of uptime and downtime, and it reflects the combined effect of reliability and maintainability. Maintenance KPIs (MTBF, MTTR)
- 02CMMS
- A CMMS (computerized maintenance management system) is software that centralizes and manages all of an organization’s maintenance activities: work orders, assets, spare parts, preventive schedules and history. It acts as a single system of record for planning jobs, tracking their execution and analyzing asset performance. CMMS software
- 03Condition-based maintenance
- Condition-based maintenance triggers work according to the actual state of an asset, measured through indicators such as vibration, temperature or oil analysis. Instead of following a fixed schedule, action is taken only when readings cross a threshold that signals developing degradation. Preventive, condition-based and predictive maintenance
- 04Corrective maintenance
- Corrective maintenance refers to work carried out after a failure or fault has appeared, in order to restore an asset to working condition. It can be a permanent repair or a temporary fix, and it stands in contrast to the preventive approach. Preventive vs corrective maintenance
- 05Downtime
- Downtime is the period during which an asset is unavailable and cannot perform its function, whether due to a planned stop or a breakdown. A distinction is often drawn between planned downtime (scheduled maintenance) and unplanned downtime, whose reduction is a major productivity concern. Reducing industrial downtime
- 06Equipment criticality
- Equipment criticality measures the importance of a potential failure by combining its likelihood of occurrence, the severity of its consequences and sometimes how easily it can be detected. It is used to rank assets by priority so that maintenance effort can be focused where the risk is highest. FMEA and equipment criticality
- 07FMEA / FMECA
- FMEA (Failure Mode and Effects Analysis), and its FMECA variant that adds criticality, is a structured risk-analysis method applied to an asset or a process. It lists the possible failure modes, assesses their effects and criticality, and then prioritizes the preventive actions to be taken first. FMEA and equipment criticality
- 08Lockout/Tagout (LOTO)
- Lockout/Tagout (LOTO) is a safety procedure that neutralizes an asset’s hazardous energies before any work begins. It involves isolating and locking the energy sources (electrical, hydraulic, pneumatic) and marking them with a tag, so that the equipment cannot be accidentally restarted while work is under way. Lockout/tagout (LOTO) in maintenance
- 09Maintenance request
- A maintenance request is a report submitted by a user to flag a breakdown, an issue or a maintenance need. Once it is approved, the manager converts it into a work order, assigned to one or more technicians. This mechanism helps channel and prioritize incoming needs before any work begins. Work order software
- 10MTBF (Mean Time Between Failures)
- MTBF (Mean Time Between Failures) is the average operating time between two failures of a repairable asset. It is calculated by dividing the total uptime by the number of failures over the period, and it serves as a reliability indicator: the higher it is, the more reliable the asset. Maintenance KPIs (MTBF, MTTR)
- 11MTTR (Mean Time To Repair)
- MTTR (Mean Time To Repair) is the average time needed to repair an asset and return it to service after a failure. It is calculated by dividing total repair time by the number of repairs, and it measures maintainability: the lower it is, the faster the recovery. Maintenance KPIs (MTBF, MTTR)
- 12OEE
- OEE (Overall Equipment Effectiveness), known as TRS in French, measures the overall effectiveness of a production asset. It combines three factors (availability, performance and quality) whose product gives the percentage of genuinely productive time compared with the theoretical potential. TPM, explained
- 13Predictive maintenance
- Predictive maintenance uses the analysis of operating data and statistical models to forecast the likely time of a failure. It makes it possible to schedule work at just the right moment, before the breakdown but without replacing parts that are still serviceable. Preventive, condition-based and predictive maintenance
- 14Preventive maintenance
- Preventive maintenance covers tasks scheduled in advance to prevent failures, triggered by a calendar or by an asset’s usage (running hours, cycles, distance). The goal is to keep assets in good working condition and reduce unplanned downtime rather than waiting for a breakdown to occur. Preventive maintenance software
- 15TPM (Total Productive Maintenance)
- TPM (Total Productive Maintenance) is an improvement approach that aims to maximize equipment effectiveness by involving all staff, including production operators. It rests on autonomous maintenance, planned maintenance and the elimination of losses, within a continuous-improvement mindset. TPM, explained
- 16Work order
- A work order is the document that formalizes a maintenance task to be carried out on an asset or a location. It describes the work to be done, the assigned person, the priority, the due date and any required procedures or parts, and it tracks progress through to completion. Work order software