The process of breaking down the script occurs after the producer

Film producer

A film producer oversees and delivers a film project to all relevant parties while preserving the integrity, voice and vision of the film. They will also often take on some financial risk by using their own money, especially during the pre-production period, before a film is fully financed.The...

 reads through the screenplay

Screenplay

A screenplay or script is a written work that is made especially for a film or television program. Screenplays can be original works or adaptations from existing pieces of writing. In them, the movement, actions, expression, and dialogues of the characters are also narrated...

 once. Then he or she goes back and marks certain elements that need to be taken care of before production, or even before pre-production

Pre-production

Pre-production or In Production is the process of preparing all the elements involved in a film, play, or other performance.- In film :...

 can begin.

Marking 1/8's

Each scene, as per slug line

Screenplay slug line

A slug line is unique to the screenplay and states numerous things about a scene. Often called a Master Scene Heading, it occurs at the start of every scene, and is usually made up of three parts.-Part one:...

, is measured into 1/8's of a page by its number of inches. Most pages of a screenplay are eight inches, so each inch is an 1/8, even if a page exceeds eight inches. The number of 1/8's is then marked in the top left corner of the scene, and circled. If a scene lasts longer than eight 1/8's, it is converted to 1. So, a scene lasting twelve 1/8's is marked 1 4/8.

Marking elements

To ease future production, an assistant director marks the elements found in each scene. This process repeats for each new scene. By the end, the producer will be able to see which scenes need which elements, and can begin to schedule accordingly. The film industry has a standard for color coding:

Element color codes

Element	Shape or color	Description
Cast	Red	Any speaking actor
Extra (Atmosphere)	Green	Any extra or group of extras needed for the background.
Extra (Silent bits)	Yellow	Any extra needed to perform specifically, but has no lines.
Stunts	Orange	Any stunt that may require a stunt double Stunt double A stunt double is a type of body double, specifically a skilled replacement used for dangerous film or video sequences, in movies and television , and for other sophisticated stunts... , or stunt coordinator.
Special Effects	Blue	Any special effect Special effect The illusions used in the film, television, theatre, or entertainment industries to simulate the imagined events in a story are traditionally called special effects ....  required.
Props	Purple	All objects important to the script, or used by an actor.
Vehicles/Animals	Pink	Any vehicles, and all animals, especially if it requires an animal trainer Animal training Animal training refers to teaching animals specific responses to specific conditions or stimuli. Training may be for the purpose of companionship, detection, protection, entertainment or all of the above.... .
Sound Effects/Music	Brown	Sounds or music requiring specific use on set. Not sounds added in during post Post-production Post-production is part of filmmaking and the video production process. It occurs in the making of motion pictures, television programs, radio programs, advertising, audio recordings, photography, and digital art... .
Wardrobe	Circle	Specific costumes needed for production, and also for continuity if a costume gets ripped up, or dirtied throughout the movie.
Make-up/Hair	Asterisk	Any make-up or hair attention needed. Common for scars and blood.
Special Equipment	Box	If a scene requires the use of more uncommon equipment, (e.g. crane, underwater camera, etc.).
Production Notes	Underline	For all other questions about how a scene will go, or confusion about how something happens.