Elevator Expert on How to Move 10k People Up a 118-Floor Skyscraper [video]

Elevator Expert on How to Move 10k People Up a 118-Floor Skyscraper [video]
youtube.com

I've often wondered what the most optimal elevator algorithm is. Imagine a scenario where a single person calls an elevator to go down, and just as they get in, a group of five people on the floor above also call the elevator to go down. We all know that the elevator would go straight down and then come back up for the people who called the elevator too late.

The elevator could actually save time by letting the person on the lower floor board, going one floor up, and letting the group board before going back down. The algorithm could factor in the number of people waiting on each floor, the time taken to travel between floors, and how many people are already on the elevator into account to optimise its route.

With multiple elevator shafts there's even more things to think about. Could one shaft serve a lower set of floors while another shaft serves a higher set of floors to minimise 'wasted' time travelling up and down? Could the algorithm take into account the time of day and the ingress/egress of people from the building? Is there a specific floor that's 'hot' and could be prioritised?

I guess the two numbers to optimise for are wait time and travel time and there will be some tradeoffs.

edit: One more thought. Time taken to travel between floors is probably not even close to linear. The elevator has more time to accelerate for greater elevation changes.

“Shafted” is how the guy already in the elevator would describe the elevator going up to get the group when he wants to go down.

[0] https://en.wikipedia.org/wiki/SimTower