Evidence Over Attestation
“Excellence is judged at the customer's fingertip, by a person who owes you nothing.”
Drucker's customer defines value; the fingertip standard says she defines it at the moment of use, with no obligation to be patient.

More lines from the same part
- “The machine can do the arithmetic but only competence knows what the number means.”
- “Clear failure states, quiet recovery, and no punishment for a customer's caution.”
- “Attaining maximum efficiency while heading in a direction no customer asked for.”
- “An agent answers the question it is given. A leader's value is in choosing the question.”