Monday, 28 October 2002

Is this elevator going down?

You know this kind of questions, most often asked by some tame idiot with a sheepish smile. Such a fool most likely pressed all buttons he could find, aiming for an sooner arrival of an elevator.

No, the elevator will not arrive sooner. On the contrary. That kind of button mania slows down the whole elevator system. The difference is huge between an elevator that can maintain speed and one that must slow down, stop and accelerate again.

What to do with these notorious button pushers?

  • drag him into the elevator and take him as far as possible into the wrong direction?
  • have him work as lift operator for remaining part of the day?
  • deny him access to the elevators and force him to hop-scotch up the stairs?
Such measures are unsuitable. What is a good alternative?

Simple: One button

For an elevator in a simple apartment building a simple system with just one button suffices. Notorious button pushers can not press the wrong button.

Complex: Fitts' law

For a large office building things get more complex.
  1. early morning everybody rushes to the right floor
  2. around lunch time there is a small rush to and from the company restaurant.
  3. During the day some may visit co-workers at another floor.
  4. At the end of the day everybody wants to reach the exit.
An idea for such complex situations:

Optimise the big streams

Create large, easy accessible, buttons.
8: office
7: office
6: office
5: office
4: office
3: office
2: company restaurant
1: reception
  • from reception to office floors
  • from office to company restaurant and back
  • from office towards exit, reception.

Allow counter-currents

Create small buttons for counter currents, at a more difficult location, for example somewhere near the most distant elevator.
  • going from one office floor to the other remains possible, but will take a few extra steps.
Most people are lazy. The few extra steps will stop idiots from needlessly pushing buttons. Fitts' law (asktog.com) works. The elevator system will be more efficient, with elevators that only stop if it is really necessary.

Till next week,