I like the old system of air-traffic control before everything was digitised. I read an article about it so I have an opinion on one aspect about it. The old system had a way of holding routing slips or whatever they were called. Part of the job of ATC is to hand over planes from one zone of responsibility to another. The way this was done in the manual system was for the person handing over a flight to place the token (whatever it's called) to one side of the person who will next have responsibility for it. The system worked well because incoming tokens could be picked up in a person's peripheral vision, but it wouldn't need to distract them from the task straight ahead of them. When they had time (of their choosing), they could glance at the token to pick up the vital statistics about it, then get back to either tasks that were in their central field of view (most pressing/urgent and most in need of attention), or they could manually move tokens from their peripheral vision closer to the central field as mandated by the urgency/ordering. This is about designing systems that work around humans in a way that doesn't require them to be hyper-vigilant at all times. Again, I just read one article, so I am definitely not an expert on this. I just found it cool.