Explain MTBF and MTTR.
Updated Apr 28, 2026
Short answer
MTBF (Mean Time Between Failures) measures reliability; MTTR (Mean Time To Repair) measures maintainability/availability.
Deep explanation
Availability and Reliability are the cornerstones of production-grade systems. MTBF (Mean Time Between Failures) measures reliability; MTTR (Mean Time To Repair) measures maintainability/availability. Ensuring high uptime requires both preventing failures and minimizing recovery time.
Real-world example
A website staying up during a traffic spike by using multiple servers.
Common mistakes
- Assuming a system is reliable just because it is available (e.g., it's 'up' but returns errors).
Follow-up questions
- How many minutes of downtime is 99.99% availability?