MTTD (Mean Time to Detect)

Mean Time to Detect (MTTD) is the average elapsed time from when an issue begins to when it is detected, whether by an automated alert or a human report. It is a measure of how quickly you learn something is wrong.

Why it matters

Detection is the first part of every outage's duration. Nothing can be fixed before someone knows about it. Long detection times often mean customers noticed first, which hurts trust. MTTD is shaped by check interval, number of monitoring locations, depth of checks and alert rules. It sits alongside MTTA (time to acknowledge) and MTTR (time to recover) as part of an incident's timeline.

Example

Three incidents in a month:

Incident A: started 10:00, detected 10:02 -> 2 min
Incident B: started 14:10, detected 14:11 -> 1 min
Incident C: started 22:00, detected 22:21 -> 21 min (customer email)
MTTD = (2 + 1 + 21) / 3 = 8 minutes

The outlier shows a gap in coverage worth fixing.

Common mistakes

• Not recording when the issue actually started, so detection time cannot be calculated. Use logs and deploy times.
• Relying on the mean alone. A few long cases can be hidden or can dominate.
• Checking only every 10 minutes, which sets a floor on detection time.

Related

• MTTA
• MTTR
• MTBF
• Incident

यह पेज सामान्य जानकारी है, जिसे हमारी संपादकीय टीम ने लिखा है और दस्तावेज़ीकरण बदलने पर अपडेट किया जाता है। सर्वर और प्रदाता अलग-अलग होते हैं, इसलिए बदलाव पहले सुरक्षित तरीके से जाँचें। देखें: संपादकीय नीति और अस्वीकरण.