Valid. However, I wonder if we don't need a system to measure if our planned actions are helping or not.
It seems to be that the idea of measuring, using a Key in the direction of a Projected Expectation is to change the Key, to reflect about the validity of the Key.
I am not in favor of Output or Outcome yet - but I am allowing room for a deeper reflection here - so that we can go back to abstract the essence of what is going on with the art and science of trying to measure/evaluate/learn our efforts towards objectives.