I'm looking for a turn of phrase to describe a situation where the powers that be wish to continue making small improvements to a process which, due to deep-rooted flaws, will never be close to accurate.
I'm working on a process for estimating the states of business objects, and there's interest in fixing some edge cases which have been noticed. This could be worthwhile, but because of missing data we're already making heroic guesses. So if implemented, we might get from 80.0 to 80.1% accuracy. If we were at 99.5%, I'd be happy to get it to 99.6%, but in the current situation it doesn't seem productive.
We have some CS people on E.SE; what would you call it when someone wants to optimize a two-second process to load data, though once loaded it will be chewed on by an inefficient algorithm for hours?
Something like "bailing the ocean" or "fixing a leaky faucet in a burning building" is close to what I have in mind. There's also "rearranging deck chairs on the Titanic," but that carries an implication that the changes are wholly useless, and that events are coming to a head.