Mean Time to Restore
Mean Time to Restore is the average time required to return a failed service, system, or asset to an acceptable operating condition.
What this term means in maintenance
Mean Time to Restore is the average time required to return a failed service, system, or asset to an acceptable operating condition.
Formula
Mean Time to Restore = Total restoration time ÷ Number of restoration events
Practical example
A utility system has 12 hours of lost service across four events.
Mean Time to Restore = 3 hours
Restore versus repair
Restoration may occur through repair, standby equipment, bypass, replacement, or another recovery method.
What may be included
The measure may include detection, acknowledgement, diagnosis, waiting, repair, testing, and return to service depending on the definition.
Difference from Mean Time to Repair
Mean Time to Repair focuses on repair work. Mean Time to Restore focuses on recovery of the required service.
Common mistake
Using the abbreviation MTTR without defining whether it means repair or restore creates confusion.
How this term differs
Mean Time to Restore is the average elapsed time required to restore the required service, which may include standby, bypass, waiting, testing, and recovery. It is related to Mean Time to Repair, but these terms describe different records, measures, roles, strategies, or decisions and should not be used interchangeably.
Related concepts
Related maintenance terms
Keep exploring connected CMMS, reliability, and maintenance planning terms.
Mean Time to Repair
Mean Time to Repair, or MTTR, is the average time required to restore a repairable asset after failure.
Operational Availability
Operational availability is the proportion of total required time that an asset is ready for use under actual operating and support conditions.
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.
Glossary FAQs
- What is Mean Time to Restore?
Average time required to return failed equipment or service to acceptable operation.
- How is restore different from repair?
Restoration may use repair, standby, bypass, or replacement.
- Why is MTTR ambiguous?
It can mean Mean Time to Repair or Mean Time to Restore, so the definition must be stated.