Mean Time To Resolution (MTTR) Calculator
Calculate the average time taken to fully resolve failures, incidents, or support tickets from the moment they are reported until they are completely resolved.
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Formula
MTTR = Total Resolution Time / Number of Incidents
Where:
- Total Resolution Time — The sum of all time intervals from when each incident was reported to when it was fully resolved.
- Number of Incidents — The total count of incidents in the measurement period.
Example: If 3 incidents took 45, 90, and 30 minutes to resolve:
MTTR = (45 + 90 + 30) / 3 = 55 minutes
Assumptions & References
- Resolution time is measured from the moment an incident is reported or detected to the moment it is fully resolved (not just mitigated).
- MTTR includes all phases: detection, diagnosis, repair, and verification/testing.
- All incidents in the dataset are assumed to be of comparable scope; mixing minor and major incidents may skew the metric.
- MTTR is distinct from MTBF (Mean Time Between Failures) and MTTF (Mean Time To Failure).
- Industry benchmarks vary widely: high-performing DevOps teams often target MTTR under 1 hour; traditional IT operations may average 4–8 hours.
- Reference: ITIL v4 Service Management Framework; DevOps Research and Assessment (DORA) metrics.
- For SLA compliance, MTTR targets are typically defined per incident severity tier (P1, P2, P3, etc.).