MTBF (mean time between failures) is a well-known parameter that can be found on nearly every datasheet. But what does a MTBF figure 156000 mean? Does it mean that an instrument runs in average 6500 days or 17 years? No – nobody has tested this and it does not mean that the unit runs 17 years!

MTBF is a measure of how reliable a hardware product or component is. A desired MTBF can be used as a quantifiable objective when designing a new product. The MTBF figure can be developed as the result of intensive testing, based on actual product experience, or predicted by analyzing known factors. The manufacturer may provide it as an index of a product’s or component’s reliability and, in some cases, to give customers an idea of how much service to plan for.