Use External Simplified Representations to store only the required sub-assemblies without modifying the original assembly. The use of external simplified representations (ESRs) minimizes the risk of accidental modifications to the top-level assemblies.

You can save simplified representations as a separate ESR assembly file. You can also check out and check in the external simplified representations in the active workspace.

While using external simplified representations in an assembly, you can see the structure of that external simplified representation with all its dependencies. You can view this information on the Details page in the workspace by clicking Structure. The Details page is refreshed to display the Model Structure Report table. The Model Structure Report is different than the Model Tree structure, as the Model Structure Report does not show the excluded objects or subassemblies. If you exclude a single component from a subassembly, the entire subassembly is not displayed in the Model Structure Report.

The Creo application identifies the external simplified representations dependencies in the assembly and also lists these dependencies in a BOM. The BOM serves as a convenient way to view a summary of the assembly. You can view, print, or save this BOM to a disk. The BOM lists the total quantity of each component included in the assembly. This quantity of a component is represented as a sum of multiple occurrences of that component in the assembly.

With a Windchill server, you can also see the quantity of each component included in the assembly in the Model Structure Report from the Details page. While using the external simplified representations, the BOM lists only the components and subassemblies, which are not excluded.