Traceability: Documentation shall be maintained to permit traceability between part serial numbers, welded assembly serial numbers, base metal lot numbers, filler lot numbers, and identification of all equipment and operators that were involved on the production of the weldment assemblies. The supplier incorporating the weldments into final delivered components or sub-assemblies shall maintain traceability between the welding lot number and any traceability/serial number used on the final delivered components or subassemblies.