MAINTENANCE GUIDE · 8 MIN READ
MTTR Explained: How to Calculate and Improve Repair Time
Mean time to repair measures the average active time needed to restore failed equipment. It becomes misleading when waiting for parts or approval is mixed into hands-on repair time without distinction.The MTTR formula
Add the active repair duration for comparable completed failures and divide by the number of repairs. Four repairs taking 2, 3, 1 and 4 hours produce an MTTR of 2.5 hours.
State whether test-running and controlled handback are included. Consistency matters more than choosing the shortest definition.
Why status discipline matters
A job waiting two days for a bearing should not appear as 50 hours of active repair. Use a waiting status for parts, access or approval, and start in-progress time when hands-on work begins.
Practical ways to improve MTTR
Improve fault information at the request stage, make drawings and history available at the asset, standardise diagnostic checks, identify critical spares and capture the actual fix clearly.
- Clear symptom
- Asset history available
- Correct skills assigned
- Critical parts identified
- Safe access prepared
- Useful completion note
| Repair | Active duration |
|---|---|
| 1 | 2.0 h |
| 2 | 3.0 h |
| 3 | 1.0 h |
| 4 | 4.0 h |
| MTTR | 10 / 4 = 2.5 h |
PUT THE PROCESS INTO PRACTICE
See honest waiting and in-progress work states
Explore the product page →COMMON QUESTIONS
Clear answers.
Does MTTR include waiting for parts?+
Some organisations use restoration time that includes all delay. If your goal is repair efficiency, track waiting separately and document the metric definition.
Should planned maintenance be included?+
No. MTTR normally concerns corrective restoration after failure.