Elementary systems functions

1. A complex system cannot be "made" to work. It either works or it doesn't.

   1. A simple system, designed from scratch, sometimes works.

   2. Some complex systems actually work.

   3. A complex system that works is invariably found to have evolved from a simple system that works.

   4. A complex system designed from scratch never works and cannot be patched up to make it work. You have to start over, beginning with a working simple system.

(Wikipedia)