the first call on a big job is an availability check. are you free on these dates. underneath it, a second conversation starts, about how many days are in the budget, and the days are nearly always a little light. nobody does it on purpose. some producers haven't run a job at this scale before. some know the number is short and are fitting it to a budget someone else set. either way, the call ends with a number of days and nobody has counted the work. then the documents arrive, and they never sit still. an old drawing, a new plan, a cancelled space, scope growing in one area while the budget shrinks in another. drawings, plans and elevations take time to turn up, and until they do nobody can pass a brief into the studio. that's normal on a live event. what hurts is having nothing to hold the movement against. the studio can feel the job getting bigger and can't say by how much. the rule of thumb is short. each artwork takes an hour. count the artworks on the deck and the matrix and you have your hours, and your hours are your days. that's your scope, as a number. some take longer and some are quicker, and they even themselves out by the time the artworker has updated the matrix and the deck. it's an average across the whole job. nobody times each file, and the quick ones pay for the slow ones. when the plan moves, the count moves with it. a cancelled space comes off. a new one goes on. the number changes while the days can still change, and the argument about whether the budget is light starts from a figure. folc. law 011: each artwork takes an hour. now you can work scope out.