Tales from the Scrum Dungeon: High Precision Rock Throwing

#scrumdungeon

This story is more of a second-hand story, but still entertaining.

I once worked with a coworker who worked on an app that tracked fluid levels in above ground oil tanks. Given the potential environmental concerns about leaking oil, the tank level had to be tracked precisely. Very precisely. Rather than accepting the rounding errors that would come from using a 32 bit floating point number, the client requested that a 64 bit floating point number to be used. They couldn't afford to be leaking oil, and not notice it. So, when the app was built, a 64 bit floating point number was used. This would tracking the tank level easily to the nearest millimeter.

So how was the tank level actually measured so accurately? An employee would take a rock, and throw it against the side of the tank. Based on the noise the tank would make, the employee would guess the approximate level of the tank.

Doooonggg!
"Eh, that's got to be about half full, I'd say."

In software development, there's often a disconnect between what the user wants, what the user asks for, what is designed, and what is actually built.

Sometimes the disconnect isn't so obvious. Sometimes it's precisely obvious.