Claude Balie had made an interesting observation on the NWLEAN discussion group.
It [overproduction] is the only one [waste] that results from a decision. You don’t decide “no quality” or “useless transportation.” You just suffer from them as you try to improve.
Interesting point.
Seems like overprocessing falls under that umbrella as well, in many cases. It might not be a recent conscious decision to overprocess, but somewhere, at some time, someone decided that those processing steps were necessary.