In mechanical as well as medical components it is interesting to know about the usually hidden failure time of a product. The failure time simply means probability the component will seize to function properly or altogether. Usually, this probability of failure increases with the duration and the intensity of use. We might know this from cars or heating systems, but airplanes and heart valves obey the aame basic statistical models. Programmed failure time is a nuisance, which works against all efforts of sustainability, Over-engineered products would work much longer than the actual use case. Locomotives with steam engines that still function well even today might serve as an example of the latter case. The issue becomes a bit more complex if we consider not only the product but each single component. Maximizing profits often leads to taking risks with failure times or failure rates over a fixed time (a more general term than the guaranteed lifetime of a product). This sounds rather abstract thinking, but in modern military equipment the consideration of failure time, self-destruction or destruction by enemy play an important role again. Failure time of military equipment has moved to the forefront of issues of equipment and is part of strategic planning, like it or not.
