If you don't know what the defect level is, how do you know when to get mad?
The cost of quality is the expense of doing things wrong.
Eliminating what is not wanted or needed is profitable in itself.
In a true zero-defects approach, there are no unimportant items.
Being convinced one knows the whole story is the surest way to fail.
Selecting the right person for the right job is the largest part of coaching.