Principlev1
Map the full value stream of a recurring process to make the
Map the full value stream of a recurring process to make the ratio of value-adding time to total elapsed time visible, because waste is invisible until measured.
Why This Is a Principle
This follows from Human memory of task duration is systematically biased and (duration memory is biased) and Knowledge that exists only in tacit form degrades without (knowledge degrades without externalization). Value stream mapping externalizes the process so you can see wait times and waste that subjective experience obscures. The principle prescribes measurement as the prerequisite to improvement.