The First AD (or 1st Assistant Director) wears many hats. While their duties can range from top-tier union features to no-budget shorts, generally speaking, if the director directs the actors, the First AD directs the set. The AD department is tasked with running the day-to-day operations via that most precious of cinematic currencies: time.
When the AD is brought onto a project, it’s their job to break down the script, organizing all of the moving pieces in a clear manner; characters, props, locations, stunts, etc. From there, they create what is called a “Stripboard,” which lays out every scene to be shot. The most important information on these strips is the WHO, WHAT, WHERE, and WHEN of any scene, so that the AD can then arrange them in the most efficient order for the schedule.