In this regard, the terminology of reliability technology is woefully lacking. First of all, the term reliability itself is confusing, since it calls to mind such phrases as “good product,” “no-defect product,” “no-failure product,” and so on. Moreover, since high reliability also means long-term use, the word also involves the length of the expected lifetime. It is dif‚- cult to feel con‚dent that a product is highly reliable if the mean time to failure (MTTF), frequently used as the lifetime index, barely meets the lifetime expected by the customer. It is also dif‚cult to differentiate reliability from the con‚dence level, and the varieties of relevant mathematics and seeming disconnection of reliability measures from real phenomena are dizzily confusing.