File referencing provides many workflow possibilities for working with large and complex scenes:
Objects, materials, and animation sequences that exist in the scene can be easily organized in a hierarchical manner based on the production requirements. A pre-planned file referencing structure allows a production team to collaborate concurrently and efficiently on their project.
Complex scenes can be managed better when divided into various multi-level referenced files. When the contents of a scene are assembled as small units that are referenced into a scene, the references can be loaded or unloaded from the scene as required. This gives you the option of loading and working on their particular segment of the scene without affecting the work of others. For example, a cityscape scene could be segmented so that one team works on the buildings and miscellaneous street props, another on the trees and vegetation, and another on the animated characters. Loading one segment of a larger scene provides additional benefits such as performance improvements.
When you create file references, you can provide the reference a unique name called a namespace. Using namespaces lets you reference the same object in a scene multiple times without the risk of creating object name clashes. See Namespaces.
Scene assets for a project ideally need exist only once, and can be reused by being referenced multiple times, by multiple users, in many different scene files if required. For example, a prop such as a tree can be referenced many times into a large scene of a cityscape, and repositioned as necessary without affecting the referenced file. Scene assets, such as models, materials, and animations, can be worked on separately without affecting assets. As a second example, a technical director creates a rigged character used for all the shots; that master rig is then used for various animations. Any issues with the rigged character can be fixed once rather than re-importing the model into many different scenes.
Complex scenes can be substituted by referencing less complex proxy scenes that can be used as simple spatial references. This improves interactivity, faster animation playback, and assists in accelerating the iterative nature of lighting and rendering tests when in production. See About proxy references.