Form follows function interprets that beauty results from purity of function and the absence of frills. This corollary is adopted by designers in a variety of disciplines.

In the theory of evolution by natural selection function follows form where genetic patterns are passed from one generation to the next with no intention behind and it is left to each organism to find use of the form that they have inherited.

Despite of which follows the other between form and function, it is essential to define success criteria for a good design.

For example in a watch,

• If the success criteria are defined in terms of speed and accuracy,the digital display is superior(Function precedes Form).
• If the success criteria are defined in terms of pure aesthetics, the analog display is superior(Form precedes Function)