[bob1029]

Semiconductor manufacturing takes this to the next level with techniques like statistical process control. Units of capacity or work can take themselves offline automatically if something falls too far out of range. Waiting for a human operator is not really feasible when the facility is mostly automated and the feature sizes are atomic scale. There are also concerns with wafers that must be processed at their next step promptly or they will become guaranteed scrap. Human judgement is too slow to sort all of this out on the inner loop.

The ability for one person to stop the entire factory on purpose is not desirable in these facilities. At least not without a quick meeting first. There isn't an actual "stop line" button anywhere. Investors and customers like Apple and Nvidia would never permit this. The best someone could do (without using a fire axe in the datacenter) is to manually whack the EMO button on all the tools in a certain area (e.g. photo) which would effectively stop the line. By the time the 2nd photo tool goes offline, half of manufacturing leads would have their pagers beeping and security would be well on their way. You could try doing this through the information systems, but they likely didn't grant you permissions to flip status flags on 400 million dollar EUV tools at your leisure.

[kqr]

Self-stopping is called autonomation (or jidoka) in lean/Toyota terms. It's born out of the realisation that automation is capable of producing mistakes at a very high rate, so anything automated needs a way to detect when it's operating outside of the narrow envelope for which it is designed, and shut itself down.