Before you add representations, save the Alembic-based caches and Maya scene files you plan to use as representations. See Prepare to create representations.
You can add assembly representations to an Assembly definition using the Outliner, scene view menus, or Attribute Editor.
To add a representation to the assembly definition
If you selected Add Locator representation, the locator appears in the scene.
If you selected Add Cache representation or Add Scene representation, Maya browses the project cache/alembic and scene directories for the files.
See Switching active assembly representations.
If Load representation is on, the newly added representation is added to the scene as the active representation. The list of available representations in the Outliner and scene view Scene Assembly menus list the new representation. The Representation List in the assembly definition Attribute Editor lists the new representation.
After adding a representation, you can modify Representation Attributes, such as the representation Label. See assemblyDefinition.