How Would You Test A Lift?


(Heather) #1

This post is completely inspired by a very fun journey at TestBash Manchester!

You know when you get on a lift and you see a sign similar to this:

The fun started when I was explaining that I appeared to be testing the lift in my hotel every time I stood in it. The first time I got on, just me by myself, it told me that the lift was full and needed to be emptied. The second time I got on, I pressed floor 13, no other button was highlighted on the panel. The lift stopped at floor 10 and told me it was floor 13. I was so confused that I didn’t manage to get out of the lift, the door closed and it started going down. You can see why I started to take the 13 flights of stairs to the room instead :sweat_smile:

Then we were leaving a meetup, someone pointed to the sign saying how many people the lift could take. As is going to happen with a group of testers, we tested the theory. You can see the results in the picture. This lift seemed to function perfectly fine with the load we tested. It announced the correct floors, we were delivered safely to the exit.

What other ideas would you have for how to test a lift?


(Will) #2

of note there’s a book about testing lifts: https://en.wikipedia.org/wiki/The_Intuitionist
(It is a good read as well)

Other things to test:

  • Reset mechanisms for floor commands
  • Effect of jumping up and down (temporarily increasing load)
  • Pressing all the buttons
  • Effect of repeatedly opening and closing the lift doors (do they have a limit, does the lift give up and just close the doors etc.)
  • Psychological effects of lift music versions of various genres (lift music Bohemian Rhapsody for example…)

(Augusto) #3

This is contextual as a single elevator in a 3 floor building solves different problems than 10 parallel lifts in a 50 storey building or an elevator in a hospital or one in a nuclear plant but I’ll try

Beyond checking whether I can go up and down and stop at the floor I select…
I would check whether the alarm bell button can be pressed unwittingly by lying over it (think a crowded lift)
I would check what happens pressing multiple buttons at the same time
I would check whether the lift is accessible to visually impaired customers
I would check whether the lift is accessible to hearing impaired customers
I would check whether if I press the alarm button somebody shows up for real
I would check what happens in case the electricity goes out
I would check that the doors stop closing and reopen if an object is obstructing them
I would check how long it takes before somebody is alerted when an object stops the door from closing after
I would check whether the elevator stops working in the presence of fire or fire alarm

On the component basis
I would check if the specifications of the cables can support the load it’s meant to support
I would check if the materials are flame resistant

Feature request:
Please allow me to undo when I pressed the wrong button, maybe by pressing it again


(Ihor) #4

Main thing is not to do stress testing. Lifts are dangerous mechanisms, take care.

Sometimes there is a requirement that lift should not operate with too few weight - child should not have possibility to elevate alone.
Lets say according to speck minimum is 40 kilos and maximum is 850 kilos.
Cases:
40 kilos - lift operates ok
39 kilos - lift alarms - too few weight (call your parents, kid)
1 kilo - lift alarms - too few weight (call your parents, kid)
0 kilo - lift alarms - too few weight (call your parents, kid)
41 kilos - lift operates ok
80 kilos - lift operates ok
850 kilos - lift operates ok
851 kilos - lift alarms too big weight
1500 kilos - lift alarms too big weight (it is not failing down, but standing still and alarms)