- I built a simple spike solution to access their service.
- I morphed this into a "sanity check" to be sure that their service really was working. Mostly, I cleaned up the code so that it was testable and deliverable without embarrassment.
- I morphed this into a "diagnostic tool" to bypass the higher-levels of the application and simply access the vendor (and optionally dump the results) to help determine what wasn't work. This involved adding the dump option to the sanity check and renaming the command-line application.
- I morphed this into a "credentials check and diagnostic tool". This was -- ahem -- merely taking the hard-wired credentials out of the application. Yes. The first versions had hard-wired credentials.
That brings us to the version in use today. The "vendor ping" application.
The default behavior is a credentials check.
One optional behavior is to dump the interface details.
Another optional behavior is to allow selection among a small number of simple interactions just to be sure things are working.
What's important here isn't that I did all this. What's important is that the deliverables, user stories and project plans didn't include this little nugget of high-value goodness.
It gets run fairly frequently in crunch situations. The actor in the story ("As system admin...") is rarely considered as a first-class user of the application. Yet, the admin is a first-class user, and needs to have proper user stories for confirming that the application is working properly.