bottom-up

bottom-up (not comparable)

1. Of or relating to a hierarchical system that progresses from multiple small subunits to a single, large basic unit.
   • 1986 June 6, Richard Feynman, “Personal observations on the reliability of the Shuttle”, in Presidential Commission on the Space Shuttle Challenger Accident, Report to the President:

     The software is checked very carefully in a bottom-up fashion. First, each new line of code is checked, then sections of code or modules with special functions are verified.

2. Of or relating to a hierarchical system in which lower levels influence higher levels.

   bottom-up management

• top-down