If you can get your hands on the HBS case study of TPS it's a great read. Details how much emphasis is put on blaming any/all issues on process, rather than people. To the extent that if a clumsy worker drops a wrench, it is assumed to be a problem with process, not that worker, and addressed immediately. The case study also describes a couple of examples of assembly line workers pulling the stop levers and how management runs over asap (every minute of stoppage is much money lost) to ask the question "why" five times in order to understand the root issue of the process breakdown.