[bluGill]

A short queue is different from a long one. Toyota keeps a box of bolts on the line - a type of queue - instead of ordering them individually as needed. However there should be just enough queue - if it backs up that is a problem.

[avidiax]

That sort of queue is fundamentally different than network queues. The individual bolts are not impatient waiting to be installed. There is no P99 bolt install latency measuring from when the bolt arrives in the factory.

You therefore only need enough bolts at each station that they won't run out before the restocker completes a lap, and such that there aren't so many that they get in the way.