What is MTTR?
MTTR stands for Mean Time to Repair – the average time required to restore a system, machine or component after a failure.
MTTR is an important KPI in maintenance, IT/OT management and production, because it directly affects availability and lost production.
🧠 How is MTTR calculated?
Formula:
MTTR = Total recovery time / Number of failures
For example: If 4 failures occurred and recovery took 8 hours in total: → MTTR = 8 hours / 4 = 2 hours
🛠 What counts as “recovery time”?
- Detection of the failure
- Diagnosis of the issue
- Repair or replacement
- Testing and validation
- Restarting the system
The clock only stops when the system is fully operational again.
📈 Why is MTTR important?
- Lower MTTR = faster recovery time = less downtime
- Essential when evaluating maintenance performance
- Important for SLAs, Business Continuity, SIL and Asset Management
- Helps with capacity planning of CMMS teams and spare parts
🔁 Related maintenance KPIs
| KPI | Description |
|---|---|
| MTBF | Mean Time Between Failures – the average time between failures |
| MTTF | Mean Time To Failure – average lifespan for single-use items |
| Availability | The percentage of time the system is available |
📌 In summary
MTTR is a key metric for measuring how quickly you can resolve a failure. The lower the MTTR, the more quickly your systems are operational again — crucial for production continuity and customer satisfaction.