The invisible target principle :
All critical system attributes must be specified clearly. Invisible targets are usually hard to hit (except by chance).
The all-the-holes-in-the-boat principle :
Your design solution must satisfy all critical attributes simultaneously.
The clear-the-fog-from-the-target principle :
All critical attributes can be specified in measurable testable terms, and the worst-acceptable level can be identified.
The learn-before-your-budget-is-used-up principle :
Never attempt to deliver large and complex systems all at once; try to deliver them in many smaller increments, so that you can discover the problems and correct them early.
The keep-pinching-yourselt-to-see-if-you-are-dreaming principle :
Don’t believe blindly in any one method; use your methods and common sense to measure the reality against your needs.
The fail-safe minimization principle :
If you don’t know what you’re doing, don’t do it on a large scale.