A Normal Product Life Cycle - Some Examples

A product consists roughly of two main elements. The function of the product – what it does or is capable of doing and the usability of the same: how it does it.

Product developments starts often focusing on the first element. Compare for example the evolution of the windows operating system. When the first windows (95) arrived we were all amazed (may I say so) with the amount of possibilities we (not Mac or Nextstep users, etc) couldn’t imagine. If you look at the latest release of windows (called vista) the amount of (functional) features is not extensive. Yet the user interface has been improved a great deal.
When comparing the four main releases (95, 98 XP and Vista) of the operating systems you could say that in the beginning the increase in functional features dominate where as in the end the non-functional and usability elements dominate in the improvements of the products.