Mean Time to Detect
Mean Time to Detect is the average time between the start of an equipment problem and the moment it is identified.
What this term means in maintenance
Mean Time to Detect is the average time between the start of an equipment problem and the moment it is identified.
Basic formula
MTTD = Total detection delay ÷ Number of detected events
Practical example
Five equipment problems had a combined detection delay of 20 hours.
MTTD = 4 hours
What affects detection time
- Operator awareness
- Inspection frequency
- Sensors
- Alarms
- Condition monitoring
- Data review
- Visibility of abnormal trends
Why MTTD matters
Earlier detection can reduce damage, downtime, safety exposure, and emergency work.
Definition
The organization should define the start of the condition and the detection point consistently.
Common mistake
Using work-request creation time as the failure start can hide the actual period before the problem was noticed.
Related concepts
Related maintenance terms
Keep exploring connected CMMS, reliability, and maintenance planning terms.
Condition Monitoring
Condition monitoring is the systematic collection and review of equipment-condition information to identify deterioration, abnormal operation, or developing failure.
Operator Inspection
An operator inspection is a defined equipment check performed by trained production or facility users as part of normal operating responsibility.
Potential Failure
A potential failure is an identifiable condition showing that an asset is beginning to deteriorate and may progress toward functional failure.
Mean Time to Detect FAQs
- What does MTTD stand for?
MTTD stands for Mean Time to Detect.
- What reduces MTTD?
Better inspections, alarms, sensors, operator awareness, and condition monitoring.
- Why does MTTD matter?
Earlier detection can reduce damage, downtime, and emergency response.