I'll add my favorite: > don't start with "that shouldn't take much time, right?" Unless you are a PM that is also making non-trivial code contributions, let t

I'll add my favorite: > don't start with "that shouldn't take much time, right?" Unless you are a PM that is also making non-trivial code contributions, let the people who are actually getting their hands dirty on a daily basis provide you the estimate. What seems simple can be complex to implement or vice versa. Asking presumptive questions like this only insults the engineers knowledge of the system and usually they are smart enough to see such underhanded pressure tactics from a mile so it only diminishes respect for you in their eyes. Just ask it straight: "how long do you think this will take?" You'll get plenty of time to question the estimate and the engineer would be more than happy to take you though the code/config to explain why what seemed simple isn't so, assuming you are genuinely interested in understanding the rationale.