The spending to make a movie is often described as the "budget". For example, Star Wars: Rogue One is given out as having had a "budget" of $200 million.
In my company a budget is not what we spend. It is what we plan to spend the next year. What we actually end up spending is usually different than what we budgeted to spend.
In movie making parlance is the "budget" what the producers planned to spend on production costs before production started, or is it a figure that approximates what they actually spent on production?
(Note: I am not referring in any way to marketing, print, digital, or any other costs. I am talking only about PRODUCTION costs.)