1. In machines, the amount of time, when operating a bank of machines, between any one of them failing. Not lifetime, as hard drive manufacturers want you to think. It is the average amount of time between failures of indivdual parts when talking about a system.
2. In biology, the average lifespan of each individual organism which has a particular set of genes or "environment of luck". An "environment of luck" can be something like all people who fly on a plane, living around individuals who want you dead in the worst way,all people who smoke, or some other demographic.
1. When punching laced cards on a bank of keypunch punched-card makers, the average MTBF is about three cards.
1. In an average house, it is normal to burn out 3 incandescent light bulbs in a month. Therfore the MTBF is 10 days.
2. Teacher:"King tut only lived to be 19."
Mocking Student:"Wow, his MTBF is in the toilet!"
2. "The MTBF of John Benet Ramsey is quite short."