BOM (bill of material)

A BOM, short for bill of material or, more commonly, bill of materials, is a structured listing of everything required to make a parent assembly or finished product. It names the subassemblies, intermediate parts and raw materials, and it states the quantity of each item needed. A Government of Canada manufacturing publication from the former Department of Industry describes it as a central reference for defining the product (Government of Canada manufacturing publication).

ISO uses the same logic. It describes a bill-of-material structure as one that enumerates the quantity of each component used in each assembly, and it notes that a product with multiple assemblies can be decomposed into its individual components through that structure (ISO 64209; ISO 78580). The term appears in manufacturing, engineering, configuration management, material-requirements planning, enterprise-resource-planning and product-lifecycle-management work.

What a bill of material contains

A BOM is a product-structure document. It sets out the relationship between a parent assembly and the components used to make it. Depending on the product, one BOM can include:

• The complete product hierarchy, from finished product down through assemblies, subassemblies and component parts.
• The quantity of each item required for the parent assembly.
• Raw materials and intermediate parts that enter the build.

Because it records quantities at every level, a BOM lets a reader see exactly what goes into one unit of a product and how the pieces fit together.

How a BOM supports planning and costing

The Government of Canada manufacturing publication ties the BOM to several production functions (manufacturing publication, C2-178-1991). It states that:

• BOMs support product definition as a central reference.
• Material-requirements planning uses bills of material, inventory data and the master production schedule to calculate future material requirements.
• BOMs are critical for accurate product costing.
• BOMs help process planning verify that the proper subassemblies are included.

For a manufacturer, this means the BOM feeds purchasing, scheduling, pricing and production routing from a single structured source.

Software bill of materials (SBOM)

BOM is also used for software. A Canadian cybersecurity publication expands BOM as “Bill of Materials” and discusses a software bill of materials for medical-device software (Canadian cybersecurity publication on medical-device software). It states that the software BOM should list custom-developed code together with the third-party and open-source software used in the software build.

An SBOM therefore identifies the software components inside a product, in the same way a manufacturing BOM identifies physical parts. Where a purchase involves connected or software-enabled medical devices, an SBOM is a relevant technical deliverable and compliance concern.

What a BOM means for a supplier bidding on Canadian public contracts

A BOM appears in Canadian government technical and supply contexts. It is not a universal clause that applies to every solicitation. In a procurement for manufactured equipment, assemblies or production planning, a BOM can form part of the technical definition or the manufacturing data package. In a procurement involving software-enabled medical devices, an SBOM can be a documentation expectation.

Suppliers should read each notice on CanadaBuys for its own requirements. The statement of work, technical data requirements, drawings, configuration-management requirements and listed deliverables show whether a BOM is needed, what level of detail it must carry and when it must be delivered. Bid teams should confirm that their engineering and production records can produce a BOM with accurate quantities and part structure, and that software suppliers can list custom, third-party and open-source components when asked.