You bastards! You started me off again hehehehe... but I had to get
this story off my chest sooner or later, so just as well... :)

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.