A part structure is a dynamic, expandable representation of a bill of material (BOM) that captures the content of a product as it evolves over time. Part structures can be large and complex, containing thousands of parts in a hierarchy of assemblies, subassemblies, and components more than ten levels deep. Part structures can also represent an entire family of product variants made from configurable modules.

Part structures are created by relating an assembly part to child parts using the “usage” relationship.