At work there are lifts (3 floors) – they keep breaking and breaking, out of order most of the time. Then I see those 2 guys carrying this card, which looks exactly like a PC card, but 2m x 2m wide. Then I go to Poland, come back and the lifts have been practically replaced, they are brand new. They behave erratically, break sometimes, but it isn't as bad as before. And then, out of the blue, they start to open the door again after closing it. This is where story begins.

I don't know when this started to happen, but it definitely started to happen AFTER new lifts were "stabilized" and considered as "fully working". The door closes, opens again, closes again and off we go. All 4 lifts (2 on each side of the building) started to demonstrate this behaviour. This has been going on for months now. Imagine going from the ground floor to the 3rd, stopping en-route on the 1st floor to pick up one more passenger. It takes easily 10 minutes to get to the top hehehehe....there were engineers working furiously and seriously on all lifts few months after this started to happen. They left and lifts still behave that way. We, techies, "workaround experts" found a ... workaround for this! Just after pressing the button you have to wave your arm in between doors. Then lift takes off after the first door closing. The only problem with this workaround is usual one: fallible human factor. I keep forgetting to wave my arm after pressing the button! And this is where the story begins.

I suspect that this huge archaic PC looking card "lift card" was replaced by some more modern and more clever combination of less hardware and more software. One would expect hardware failures to be to certain extent erratic, accidental and unique. Hard disk failure can manifest itself in many different nearly unique ways. So this is my first point: ALL lifts behave in the same way, and their behaviour is VERY consistent. That's the first hint me thinks. The second clue is that, despite working hard on it for a week, engineers didn't manage to fix or even change the behaviour of EVEN ONE of those lifts. And this is where the story ends.

Punchline: This is what the difference between hardware and software is.