The Assembly Library maintains all assemblies and assembly revisions. In the library, you can create a new assembly, new revision, duplicate a revision, mark a selected assembly as current, and delete an assembly. You can also modify the design files for an assembly (BOM, Gerber, or ECAD, for example), change part types, manage the Approved Manufacturer List (AML) and Approved Vendor List (AVL) of parts, and revise an existing assembly.