In 1955, Cyril Northcote Parkinson wrote what has become Parkinson’s Law: “Work expands so as to fill the time available for its completion.” The background on this is on Wikipedia.
Lean organizations should have a keen sense to look for this law because it will be fertile ground for improvement. A lot of front-line workers will not tell you they are stretching the work out throughout their shift because they may not realize they are doing it and it might be perceived there is not enough for them to do which may threaten their job.
It might be obvious there is waste involved when this law is in effect but it can be sneaky to find where it is happening. This law does not scream there is a problem going on so you have to go to Gemba and look for it (almost like an exterminator). A good place to start is to ask staff what busy work they do. Remember the Lean adage “No problem IS a problem” and investigate to find this sneaky waste!
My 2009 Hansei: Scarcity inspires creativity and innovation. How can I help harness that inspiration?