How would you design an interface for a 1000 floor elevator?

Its not a 10% increase in complexity. Its 10 times as big.

This is a pretty broad question. Its simpler if we can distill down the scope of what we aim to do here:

Now that we have a loosely defined structure to work with, lets kick things off with the first idea that comes to mind.

A thousand buttons

The elevator has a 1000 buttons, one for each floor. Pretty simple, its just an existing design scaled up. You press the floor # where you want to go. Lets see how many total buttons we might have :

Lets take a look at the corresponding grid that would form:

A 10*100 grid to place all the buttons for the floors. This gives perspective to the nature of the problem we are dealing with.

Uh oh. Too long. Way too long, and it doesn't even take into account the open / close / alarm buttons yet!

If you were to print out this image to scale, it’d be taller than the height of an average human (or else you’d be dealing with very tiny buttons). So a 10*100 grid is obviously not practical.

Cons:

What if variations were a bit different? Would a different grid help us? What about a 20 * 50 grid? It might solve (just barely), #1 on the list above but #2 and #3 would still exist.

A better solution

So if laying out all the floors doesn’t work, what other things can we do? There is an alternative. You could enter the floor number you want to go to, via a keypad just like in an atm machine. Definitely sounds better than having a thousand buttons. Lets see how this can potentially look like:

Lets break down the components here:

States for the keypad.

The “Add” and “x” buttons on the keypad are color coded so that attention is bought to them when the user starts punching the floor number. I am assuming here that these elevators need a keycard access to private floors. An alternative could be that instead of a keycard (and thus the need for that dedicated slot), private floors are protected by a 4 digit pin. In that case the lcd screen would prompt you to enter the pin once you enter the floor number and press “Add”.

States for the lcd display.

The LCD screen on the right could be potentially used to display more information. Things like the speed of the elevator or the estimated time to the next floor or the brand logo of the elevator company. I have excluded them from the design since they are not essential to the workings of the interface. Some questions might arise with the visualization I have used here for displaying the floors to which the elevator is travelling. What are the dots between the numbers? Each dot represents a floor, and as you keep adding floors from the keypad, the dot is replaced by the floor number. This gives users the feedback that their floor has been successfully entered into the system. What if someone adds in all 1000 floors? The text size of the display would simply scale down to accommodate all the 1000 numbers. This could also work as a fish-eye lens where the current floor (indicated in green) has a bigger text size than the rest of the list.

Other notes

In case you wanted to cancel a floor.

I won’t go into much detail about the emergency and maintenance buttons, as I really don’t know which ones are essential and which ones are not. I have excluded any “call cancel” button from this design as I wasn’t totally sure its needed. Any buttons or knobs that are reserved for maintenance, I’d suggest being put away behind a hidden panel which can be opened by a key that the maintenance crew carries. These are buttons which are used rarely and it helps keep the interface clean. I have positioned these buttons at the very bottom because in case of an emergency you’d want anyone to be able to access these buttons, and that includes small kids (although I agree, its not fun when kids walk in and playfully press every damn button in the elevator..) Also note, I added in icons to these buttons and positioned them far from the rest of the buttons in the interface to make sure they stand out from the pack and are never accidentally pressed.

To wrap things up, lets put the design in perspective :

Pros

Cons

Overall, this solution works well for what it is, a quick way for multiple people to navigate between a large number of floors. Of course, if I was looking to actually implement this in real life, I’d go the multi elevator, double decker car route for efficiency purposes. Although that might not make a significant difference when it comes to using the interface I propose. Ultimately, its the question that needs more structure to it. Depending on the nature of use cases, the interface to operate the elevator(s) can vary.

Product Design @ Facebook. Previously @ Paperlesspost. www.tarunchakravorty.com

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