A hotel I recently stayed at scheduled elevator stops rather than relying on the traditional elevator heuristic we’ve used since the dawn of technology (Press button, get next elevator going in your direction). That got me thinking. It’s 2014. Why are we still using suboptimal elevator scheduling heuristics? They didn’t do it this way on The Jetsons, did they?
The hotel uses an innovation from the Otis Elevator Company. You enter the floor you want to go to instead of pressing the up or down arrows. There wasn’t much of a learning curve. The floor you entered will almost immediately pop up on one of the screens above one of the available elevators. You then wait for that elevator to arrive and take you to your destination. This minimizes waiting – the potential time savings in a skyscraper are enormous, especially at the tail of the distribution.
I do not know the algorithm used by the elevators. It was certainly a heuristic as opposed to, say, an optimal policy found by dynamic programing, but the heuristic seemed to work very well. I never had to wait longer than 5 seconds for an elevator.
Interestingly enough, some people find efficient elevators annoying. I found a YouTube video about the elevators called “The highly annoying elevators at Chicago’s Swissotel” (see below). Interestingly, the main complaint in the video is that you cannot change your mind about what floor you want to go once you are riding in the elevator (something that has never happened to me ever – I know where I am going!). Another potential complaint is that the first elevator to arrive is not necessarily the one that will take you to your destination. That is an issue with the old school elevators, too (the first elevator may be going up when you are going down). I would have guessed that in general people would like to wait less, but it seems like people would tolerate longer waits rather than embrace change.
Of course, the problem with elevators is the complaints, not the waiting time. If a new elevator paradigm is too disruptive, then maybe it’s not an improvement even if waiting times go down. But I am a fan of this particular efficient elevator system.
Would you like to see more efficient elevators?