> the only safe thing to do when you don't fully understand the system and cannot reason about it Well, the other option (the most sane one, in fact) would be

> the only safe thing to do when you don't fully understand the system and cannot reason about it Well, the other option (the most sane one, in fact) would be to not mess with it until you understand it and can reason about it - but in every corporate "how long is that going to take"/"what can we do to speed this up"/"why aren't you finished yet" quick-and-dirty-ocracy, that's not an option unless you can do that in about a day.