A scientific and technical revolution has begun that is based upon the ability to systematically organize and manipulate matter on the micrometre length scale. We do not have a great deal of information about the useful life of these sophisticated products even though they are flooding the market. Conventional reliability theories need to be restudied to be applied to micro-engineering. A confident use of these technologies relies on our capacity to better understand their fault mechanisms, and our ability to deduce related fault models.