MTTD
Mean Time To Detect
MTTD (Mean Time To Detect) measures the average time from when an incident begins to when your team becomes aware of it.
How to Calculate MTTD
MTTD = Time of detection - Time of incident start
This can be tricky because you need to know when the incident actually started, not just when you noticed it.
Why MTTD Matters
Detection time is often the largest component of total incident duration:
Total incident time = MTTD + MTTI + MTTR
If you can detect issues 10 minutes faster, you've effectively reduced total incident time by 10 minutes-regardless of how fast you fix things.
The Customer Detection Problem
The worst-case MTTD? When customers detect issues before you do.
- Customer-reported incidents have 3x longer resolution times - They damage trust and reputation - They indicate monitoring gaps
How to Reduce MTTD
1. Implement comprehensive monitoring - You can't detect what you don't monitor 2. Use anomaly detection - Catch unusual patterns automatically 3. Synthetic monitoring - Test critical paths continuously 4. Centralize operational visibility - See all events in one place 5. Enable real-time alerts - But balance with alert fatigue concerns