PLM bill of material (BOM)

A list of all the components and subassemblies that go into a parent assembly. It is the subset of a structure that includes only the physical items. A BOM includes the child item at a particular find-item location, the child items quantity and unit of measure, and related information such as reference designators. When ERP systems refer to their BOM, the reference is generally to the currently-loaded list of items, or (at most) the next immediate change at a specified future effectivity date. ERP systems typically do not keep a historical record of a BOM's evolution. PLM, on the other hand, is specifically designed to provide a full audit trail of all changes to the BOM, including when and why it was changed, which change form changed it, who approved the changes, how affected items were dispositioned, and the total recurring and non-recurring cost.