“It is useful to think of the operator [worker] as a surgeon. Obviously, a surgeon needs to focus completely on the patient. The last thing you want is the surgeon to be distracted by having to go looking for an instrument or material. …Nurses place in the surgeon’s hand exactly what is needed next, and the surgeon does not even turn around. That is the exact ideal for an operator in a plant—everything needed should be available within easy reach without turning away from the work.” 

The Toyota Way 2nd Edition by Jeffrey K. Liker (McGraw Hill, 2021) p. 149.