Source : Free On-Line Dictionary of Computing

top-down design
     
         (Or "stepwise refinement").  The software design
        technique which aims to describe functionality at a very high
        level, then partition it repeatedly into more detailed levels
        one level at a time until the detail is sufficient to allow
        coding.  This approach to software design probably originated
        at {IBM}, and grew out of {structured programming} practices.
     
        (1996-08-04)