Mean Time To Repair
Mean Time To Repair (MTTR) is the average time required to restore a failed asset to full operational functionality, calculated as total repair time divided by number of repairs. It measures maintainability in industrial maintenance, with lower values indicating faster repair processes.
In shop floor maintenance, MTTR is recorded in CMMS by logging start time (failure detection or hands-on repair) and end time (asset verified operational). It evaluates maintenance team performance, optimizes spare parts inventory, and refines preventive maintenance schedules. MTTR quantifies downtime duration, distinct from MTTF (failure-free operation) and MTBF (uptime between failures).
Does MTTR include administrative/logistic downtime (e.g., waiting for parts)?
Standard MTTR excludes Administrative/Logistic Downtime (ALDT); it focuses on active repair time from diagnosis to restoration.
How does MTTR differ from Mean Time To Recovery (MTTR)?
They are often used interchangeably, but 'Recovery' may include full service restoration including testing, while 'Repair' emphasizes the physical fix.
Why is MTTR critical for asset reliability?
It directly impacts availability (Availability = MTBF / (MTBF + MTTR)); reducing MTTR increases operational uptime.
Can MTTR be optimized without reducing MTBF?
Yes; MTTR reflects repair efficiency, while MTBF reflects failure frequency. Improving technician training or tooling reduces MTTR independently of MTBF.