Bill of Materials (BOM)
A bill of materials lists all components, raw materials and quantities that go into manufacturing a product.
Bill of Materials (BOM): Not to be confused with
A bill of materials is NOT the routing. The BOM describes the "what", meaning which parts go in at which quantity, the routing describes the "how", meaning operations, times and machines. Only together do they form a complete production specification.
The Association for Supply Chain Management’s dictionary defines the bill of materials as a complete, formally structured list of the assemblies, parts and raw materials of a product, together with quantities (Source 1). In multi-level bills of materials, assemblies can in turn consist of their own sub-assemblies, which is the foundation for every MRP calculation.
For manufacturers with a high degree of product variance, for example in Manufacturing, how well the bills of materials are maintained directly determines the accuracy of costing and material requirements.