Manager: We (meaning you) need to do task A. How long will it take?
Me: Task A will take X days to do.
Manager: That seems awful long.
Me: How long do you think it should take?
Manager: It surely could not take any longer than Y days.
Me: Ok, it seems you have an answer to your question then.
Later:
Manager: It’s been Y days, why isn’t task A done yet?
Read Software Estimation by Steve McConnell and recommend it to your manager:
The person doing the work the one best suited to estimate it.
Also, start tracking estimated vs budgeted time in some searchable system.
Next time this comes up, look up how long it actually took to complete a similar task instead of thoughts and prayers.
If boss won’t track historical budget vs actual, track it yourself.
The way we estimate on my team is to break tasks down into related subtasks that will take one day or less, then add up all the subtasks. It’s worked pretty well.
That pattern is also recommended in the book. Break down estimates into chunks of 5 hours or less.
With lots of smaller tasks, estimates tend to both be more accurate due to smaller scope, and some of the over/under inaccuracies will cancel out.
That’s a really good budgeting idea. My worst boss wanted the estimate accurate to within fifteen minutes. He churns through employees like popcorn.