What do you do when a manager asks you for an estimate about a project's release or budget? What you should be doing is responding with a question: What’s most important to you?
You can have only one number-one priority in any given project or program. You might have a number-two priority right behind it and a number-three priority right behind that, but you need to know where your degrees of freedom are.
Your manager can choose to rank the feature set first, or time to release, or cost, or a low number of defects, etc. It doesn't really matter what is determined to be the most important focus, so long as you know what it is and you only have a single number-one priority.
If management has not thought about the constraints, they may be asking employees to cram in too many features with insufficient time, given the requested date to release, low number of defects, and expected cost.
The time to release is dependent on the number of people, their capabilities, and the project environment. You can make anything work, but it won't have the results you wanted. This is why estimation of the budget or the time to release is so difficult.
If you really want to estimate a date or a budget, you need to have these preconditions:
Once you’ve met the preconditions, you can estimate more accurately.