Failing the Smell Test


August 17, 2010 by Mike Hillwig

In addition to being a DBA, I’m a bit of a travel geek. I have a great love of airplanes, aviation, and travel.

Today, I was looking at flights and saw something that made me think that it was a total violation of constraints.

Just looking at this made me cringe. US Airways flight 0729 departs London’s Heathrow, stops in Philadelphia, and then continues onto Boston. Flights with intermediate stops are common. Heck, Southwest flights are notorious for going coast-to-coast with multiple stops along the way. But in most cases, that flight is operated by same plane. In this case, the flight doesn’t stop in Philadelphia. If you look closely, you depart in Philadelphia and get on an entirely different aircraft. It’s not just a different physical plane–it’s a whole new aircraft type. You’re going from a widebody Airbus A330 onto a regional Embraer E90. This is what I call failing the smell test. The data construct just doesn’t make sense.

We’re facing a very similar situation with my company’s ERP system right now. We make technology devices and the software that runs them. Somewhere many years ago, when we started selling high availability pairs, instead of selling two devices with a discount, someone in marketing decided we would sell them as a pair. This has been a complete nightmare in terms of data. Our ERP system doesn’t allow two serial numbers for a part. The first serial number is recorded in the ERP system and then the second one lands in a spreadsheet somewhere. The folks in customer support go crazy when they can’t find the serial number of the second item in the pair.

I’ve seen a lot of conflicts between technology and marketing people in situations like this. Unfortunately, we lose all too frequently in these situations. In these cases, we need to really think through the process. Had someone looked at our problem from the customer support perspective, we might have been able to convince marketing that this was a bad idea. It should have failed the smell test at inception.

  • Tom

    Multiple US airlines seem to like the continuing-flight-number / different-aircraft scenario.

    How about:

    – flights that use the same number for each direction of an out-and-back. ExpressJet seems to do this, e.g. BTA5823,

    – flights that take more than 24h from departure to final arrival, e.g. QF1 & QF2, London-Bangkok-Sydney, such that more than 1 plane operating the same flight number can be airborne simultaneously. (To be fair, I think all examples of these with current aircraft technology would have at least one intermediate stop. However, I’d also think this situation would have been much more common before the introduction of jet travel.)

    Maybe you just need to think of different keys…