The process of breaking down the script occurs after the producer reads through the screenplay once. The producer or a first assistant director reviews the script, and marks certain elements that need to be taken care of before production, or even before pre-production can begin.
Each scene, as per slug line, is measured into 1/8s 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 1/8s is then marked in the top left corner of the scene, and circled. If a scene lasts longer than eight 1/8s, it is converted to 1. So, a scene lasting twelve 1/8s is marked 1 4/8.
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: