Leveling DFDs: how to factor a system
The BLACK BOX concept:
- you know the inputs it expects
- you know the outputs it should give back
- you know its function (what it does)
- you do not need to know the specifics to use it
Controlling complexity of black boxes
- each box should solve one well-defined piece of the problem
- each box should be easy to understand
- connections should be made as simple as possible