Effektivität und Effizienz

Effektivität: Die richtigen Dinge tun.
Effizienz: Die Dinge richtig tun.

Peter Drucker:
There is surely nothing quite so useless as doing with great efficiency what should not be done at all.
For manual work, we need only efficiency. The manual worker can always be judged in terms of the quantity and quality of a definable and discrete output, such as a pair of shoes.