About Branch Links
A structure file (PVS or PVZ) can contain references to other structure files. For example, a structure can reference a Creo Parametric positioning assembly. The references to the other structure files are branch links. Branch links can reference files on your local hard disk or files from Windchill. Branch links contain all the descendants of a part.
Branch links can be resolved or unresolved:
Resolved branch links—Reference to the external structure file is retrieved and loaded into the view. The corresponding substructure is visible in the Structure Tree.
Unresolved branch links—Reference to the external structure file is not loaded into the view, and is not visible in the Structure Tree.
When you expand a Structure Tree branch, you reload the external structure files into the tree. The corresponding substructure is visible in the Structure Tree.
To make large assemblies more manageable, you may want to collapse one or more branch links. To further minimize the Structure Tree, you can unload or unlink branch links.
By unlinking or unloading branch links, you collapse all nodes that reference the file and hide the representation in the Model view. However, the information is handled differently in the cache and in the memory:
• 
Unlink Branch Links—Preserves the file.
• 
Unload Branch Links—Deletes the file.
To Unlink, Unload or Reload a Branch Link
1. In the Structure Tree, select a loaded branch. The branch is selected.
2. Right-click and then select an operation:
The structure updates.
Reload Branch Links