We are being ruined by the best efforts of people who are doing the wrong thing.

When a system is stable, telling the worker about mistakes is only tampering.

The most important things cannot be measured.

Change the rule and you will get a new number.

Whenever there is fear, you will get wrong figures.

It is a mistake to assume that if everybody does his job, it will be all right. The whole system may be in trouble.

Without theory we can only copy.