Equipment Downtime
Equipment downtime is the period when an asset is required or scheduled to operate but is unavailable or unable to perform its intended function.
What this term means in maintenance
Equipment downtime is the period when an asset is required or scheduled to operate but is unavailable or unable to perform its intended function.
Types of equipment downtime
Downtime may be:
- Planned, such as approved maintenance or changeover
- Unplanned, such as breakdowns or unexpected process stops
- Full, where the asset cannot operate
- Partial, where output or capability is reduced
Defining the measurement
Downtime should have a clear start and end rule. For example, unplanned maintenance downtime may begin when production stops and end when the asset is repaired, tested, and released back to operation.
Practical example
A packaging line stops at 10:15 because of a drive fault and restarts at 11:05 after repair and testing.
Recorded downtime = 50 minutes
Why reason codes matter
Categorizing downtime helps distinguish maintenance failures from:
- Material shortage
- Quality hold
- Operator delay
- Utility loss
- Setup
- Process conditions
- Planned maintenance
Downtime percentage
Downtime percentage = Downtime ÷ Scheduled time × 100
Common mistake
Recording only total downtime without the affected asset, cause, and action taken makes the number difficult to investigate or improve.
Related concepts
Related maintenance terms
Keep exploring connected CMMS, reliability, and maintenance planning terms.
Equipment Availability
Equipment availability is the percentage of required or scheduled time during which an asset is capable of performing its intended function.
Mean Time to Repair
Mean Time to Repair, or MTTR, is the average time required to restore a repairable asset after failure.
Breakdown Maintenance
Breakdown maintenance is repair work performed after an asset has failed and can no longer perform its required function.
Glossary FAQs
- What is the difference between planned and unplanned downtime?
Planned downtime is approved in advance. Unplanned downtime results from an unexpected failure or interruption.
- When should equipment downtime start and stop?
Use documented rules, such as from loss of required operation until the asset is repaired, tested, and released back to service.
- Should reduced-speed operation count as downtime?
It may be measured separately as performance loss unless the organization defines it as partial downtime.