Mean Time Between Failures (MTBF)

MTBF is a statistical prediction of reliability, usually expressed in hours. It does not mean a specific unit will last that long; rather, it indicates the expected average time between failures for a large population of units.

Component vs. System MTBF

A motherboard might boast an MTBF of 300,000 hours. But if you add RAM, an SSD, and a Wi-Fi module, the system-level MTBF drops significantly. In a series reliability model, any single component failure causes a system failure.