Obsolescence
Design life is related to but distinct from the concept of built-in obsolescence. The latter is the somewhat more nebulous notion that products are designed so as to become obsolete—at least in the eyes of the user—before the end of their design life. Two classic examples here are digital cameras, which become genuinely obsolete as a result of the very rapid rate of technological advances, although still in perfect working order; and non-digital cameras, which are perceived as obsolete after a year or so as they are no longer "the latest design" although actually capable of years of useful service.
Read more about this topic: Design Life