MTBF (Mean Time Between Failure) is a statistical method developed and administered by the U.S. military for purposes of estimating maintenance levels required by various devices and systems. Since accurate statistics require a basis of 'failures per million hours of operation,' an MTBF estimate on a single device is not very accurate; it would tak... Found on http://www.probertencyclopaedia.com/browse/GM.HTM
or Mean Time Between Failures is a theoretically calculated value which considers all the components used in the construction of a product. It may also be a statistically calculated value derived from real operational data collected from a sufficient number of the same product.
Found on http://www.sensorsone.co.uk/pressure-measurement-glossary.html