top-down design

from The Free On-line Dictionary of Computing (8 July 2008)

top-down design
stepwise refinement

   <programming> (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)