The principles and methods for improvement are the same for service as for manufacturing. The actual application differs, of course, from one product to another, and from one type of service to another.
The worker is not the problem. The problem is at the top! Management!
You can not hear what you do not understand.
All models are wrong; some models are useful.
A rational prediction has an explanation based on theory.
A leader is a coach, not a judge.