What business rule is the most important? For whom, and when?

This morning I was in a hurry. Not only did I have to get to my train on time, I also had to refill my train pass with another 30 days, before I got on the train. And of course I wasn’t the only one in the same situation when I came to the ticket office, so I had to wait for my turn.

As always when facing these kind of obstacles in my way, the natural thing for me is to find a better solution. This time I had to get a quicker way to refill my card. Looking at the small vending machine, where you normally buy ordinary tickets for a cheaper price with a card filled with money, I saw a sticker that I have never seen before. Apparently they upgraded the machine to be able to refill my kind of card as well with credit cards. YAYE! The last time I remember this machine getting an upgrade was when you started to be able to refill the money cards with money from credit cards.

So, happy with my new knowledge, I followed the instructions for refilling.
“Press refill”
“Swipe credit card”
“Insert train card”
Observing the fact that the machine understands what kind of card it is
“Press Ticket”
WÄHHH!
*Machine spits out card*
“Your purchase exceeds 850 kr” (Yes, of course it does, this card costs 1060 kr.)

Not so happy anymore, I have to try it again, to see if it was actually happening what I saw.

I start to think about how this could happen in an upgrade of software. From before when these machines were new, you were only able to buy tickets for a train ride. You could buy family tickets etc, but the fact is that a regular one-way/one-person ticket never exceeded 78 kr (or something), which used to be the maximum price for in-region travel, pretty much did not get you above 850 kr. One question would be, when did they put this limit? Was it when they started to take credit cards, or was it in there from the beginning, not allowing you to use the refill cards for more than the limit?

Some other relevant questions would be:
Who decided on the limit 850 kr? Legal issue?
And why this amount?
Wouldn’t it have been easier to have 1000? This would of course also have been a wrong amount for my monthly card, but at least it would have made sense as a maximum value.

Then we got the business value when they realized that the customers could refill their monthly cards in these machines. The cost of having employed people doing this must be soo much higher than doing the development for upgrading the machines. But did it cost too much to test it properly? Did noone even consider old business rules (ex 850 kr limit) as a risk when implementing new business rules for the refills?

I returned to another machine to take a photo of it later today. Since I was not in the same hurry, I realized the sign above it stating the obvious bug as a technical malfunction. But the thing is that this sign was not present at the first machine where I was this morning. If I would have seen it this morning, I would probably not have gotten frustrated like I did.

So I guess they realized the bug in production by the customers, but they could have the documentation for the bug at all machines. Like the company needs worse reputation than they already have.