Correlation/Causation

I think there are two big difficulties in the IT world.  Both are especially relevant to the C-Store world.  One is turf wars.  Turf wars are when departments are more concerned with covering their own behind rather than working with other departments.  You can only hope to fix that one, but it's not likely going to happen.

  The second issue is this: correlation does not equate to causation.  In laymans terms: just because two things happened around the same time doesn't mean one caused the other. I had a failed Verifone Commander install a few days ago.  I could never get the gas pumps to talk.  They happened to be Gilbarco Advantages.  This was my first site with more than 16 pumps.  Interestingly enough, this was my first site with more than 12 pumps.  That number becomes relevant in a minute.

Anyways, credit processing worked fine.  Ran like a champ.  But I couldn't get the pumps to talk.  The site was Gilbarco with a PAM 1000 and 2 D-Boxes.  I spent a long time trying to get it to work, but never could.

So I decided to put the old equipment back in place, and attempted to get it back to working.  Pumps still wouldn't talk.  I finally called in some pump techs, and we got 5 of the 10 dispensers communicating.  We decided that was good enough for now.  After the weekend, I called the pump company and scheduled them to come install the site.

The install was done in 4 hours.

What happened?  Remember that magic number 12 I was talking about before?   The PAM 1000 can only address 12 pumps with a single board.  You can add more boards to talk to more pumps.  But you start over the pump addressing.  This is not information I knew prior to installing.

So, when I plugged 16 pumps into one board, nothing would talk.  Why?  Because there were duplicate addresses out on the system.  Not only that, there were multiple duplicate addresses.  Because fueling position 13-20 had internal pump number of 1-8.

The fix (had I known the situation) would be renumber the pumps.  Which is what the pump company did.

Or, start over on the 2nd fuel board at position 13.  That would have solved the issue quite easily.

So where does causation/correlation come in to this argument?  Simple.  The belief that changing out the point of sale system caused the pumps not to communicate.

I'm not a pump tech, and that's rare in this industry.  I am a Verifone VASC and a CCENT, but my knowledge stops at the 2 wire going to the pump.  I have to work with other pump techs and hope they know what they are doing.  And hope that they aren't having turf wars.

As a footnote to the story.

As I was leaving the parking lot, I noticed the site was changing gas prices.  After getting back ot hte office, I had conversations with 4 different people about why the price sign wouldn't change, and no one seemed to believe what I was saying.  The gas price sign was changed by a key fob.  Always has.  I didn't mess with that during this install.  But now, the gas price sign wouldn't change.

It took a bit of convincing to for people to realize that the gas price sign was at fault, not the point of sale system.

Anyways...