MTTF, or Mean Time to Failure, measures the expected lifespan of a system or component that is not repaired after failure — it is replaced instead. MTTF is commonly used for hardware components like hard drives, power supplies, or single-use devices.
MTTF is calculated by dividing the total operational time of multiple units by the number of units that failed. For example, if 100 hard drives run for a combined 1,000,000 hours and 10 fail, the MTTF is 100,000 hours.
In software and cloud services, MTTF is less commonly used because services are repaired rather than replaced. MTBF (Mean Time Between Failures) is the more appropriate metric for repairable systems. However, understanding MTTF is important when evaluating infrastructure components and planning for redundancy.
