A key benefit of Creo Elements/Direct Model Manager over its predecessors is the ability to save assemblies from the top down. After creating an assembly, saving the top level assembly will also save all subassemblies and parts that are children to that assembly.

Another benefit of the top-down save is the ability to save structure changes up through the structure. When you create a new version of a model, the parent of that model is saved with the new model linked to the parent structure. If you save a sub-assembly as a new version, its parent is also saved as a new version.