This is a post by Katelyn Stevens on the PTC site.
1. Retain parent/child assembly relationships
You can easily retain parent/child relationships by using the Replace functionality, which instantly increases your productivity. Doing so automatically enables you to replace any component that is part of a family table with another instance of that family table. Replacing components by family table is a fast and easy way to swap components in and out of an assembly. This is a common method when working with standard hardware libraries that are often created with family tables.