The One-Hundred Floor Elevator Problem

The One-Hundred Floor Elevator Problem is an exercise in the code necessary to ensure the wait time for an elevator throughout the building is not excessive.  I've never sat down to work it through but it's fascinating maybe like a Rubik's Cube but I never bothered to sit down to work one of those through.

Say our One-Hundred Floor Building has one hundred people on each floor.  There will be more per floor on the lower floors than on the upper floors but, on average, it comes to one hundred per floor.

That means the building, if fully-occupied, would have ten thousand people in it, distributed on a calculable basis, from bottom to top.

Say you have ten elevators for the building.  Each of those can carry about twenty people since they will average collectively about two tons.  Therefore, the greatest number of people you can move at once is about two hundred.

If the building is mostly for workers and the shift ends at five o'clock, that building will go to complete gridlock when they try to leave to go home.

These kinds of gross calculations will be necessary for the builders to have any chance of supporting the number of people who will be in the building but that's just the first part of the One-Hundred Floor Elevator Problem.

The second part is tuning the elevator frequency once the construction has completed.  If the arrival frequencies aren't correct then it won't matter how many elevators can be used since they aren't being used efficiently and you will still get a backup.

The elevator frequency has to be predictive in terms of recognizing some percentage of the workers will roll out at certain hours so arrival schedules may need to accommodate that.  There also has to be reactive capability to analyze and handle unanticipated demands.

Some of you get off on the New York Times Sunday crossword puzzle but I get intrigued by this sort of thing.  Neither pastime really accomplishes anything but can be interesting to consider.

Ed:  it's a great one to consider when you're waiting for an elevator!

Don't you do that?  I think we all do.

Cranky Person:  see ... that elevator on the end ... it hasn't come by this floor the whole time.  What the hell is up with that, huh?

I am so sure you have heard that or thought it yourself.

We all think at that time, man, I could make it work better than this worthless crap so then we start thinking, well, could we really.