There's an anti-pattern for this (I don't recall it's name off the top of my head) for which the gist is:

Manager: Can you get task X done in Y weeks?

Geek: We can get task X done in Y weeks provided that: conditions a through z are met; we get buy in from stake holders Alpha, Bravo, and Charlie; if the stars are in alignment; and, we get enough goats/interns for the requisite blood sacrifice.

Pretty straight forward, right? However, from my own experience, this is how the above conversation is interpreted:

Manager: Can you get task X done in Y weeks?

Geek: We can get task X done in Y weeks blah blah blah blah blah blah blah.