Momus

Successive Refinement
An approach that relies heavily on subroutines is called “Successive Refinement.”

 The idea is that you begin by writing a skeletal version of your program
using natural names for procedures for data structures.

Then you write versionsof each of the named procedures.

You continue this process to greater levels of detail until 
the procedures can only be written in the computer language itself.

Momus

Simplicity is the primary measurement recommended for evaluating alternative
designs relative to reduced debugging and modification time. Simplicity can be
enhanced by dividing the system into separate pieces in such a way that pieces
can be considered, implemented, fixed and changed with minimal consideration
or effect on the other pieces of the system.