Glossary
What Is BOM? Bill of Materials Definition
A BOM, or bill of materials, is the structured list of materials, components, subassemblies and quantities needed to build an end product.
A BOM (bill of materials) is a structured list of the raw materials, components, subassemblies and quantities required to make an end product. It can represent product structure, revisions, and the relationship between parent assemblies and lower-level items.
BOM Explained in Plain Language
A BOM is a parent-and-child list: each assembly points to the items beneath it and the quantity of each. A bicycle BOM, for example, lists the frame, wheels and drivetrain, then breaks each wheel into rim, spokes, hub and tire.
A BOM lists what is required; a bill of process describes how the product is made. A parts list may be flat, while a BOM generally preserves structured product relationships.
Typical BOM Values and Variants
| Parameter | Typical range | Source |
|---|---|---|
| Quantity per parent | One or more units; product-specific | DOE BOM definition[7] |
| Structure level | Multi-level, from finished item to lowest component | DOE BOM and Oracle manufacturing documentation[7][9] |
| Revision | Controlled by product lifecycle system; unverified | Organization-specific; no universal value verified |
How a BOM Is Used in Manufacturing
Engineering creates a design BOM from CAD and product requirements. Manufacturing converts or supplements it into a manufacturing BOM that supports assembly sequence, production planning and operations.
- ERP or PLM systems maintain versioned BOM records with traceability, permissions and revision control.
- Data quality depends on disciplined item master maintenance.
- Engineering-to-manufacturing changes require controlled approval and release status.
- BOMs are reconciled against drawings and physical assemblies.
Related terms
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FAQ
Common questions
What does BOM mean?
BOM means bill of materials: a structured list of the raw materials, components, subassemblies and quantities required to make an end product.
What is included in a BOM?
Materials, components, subassemblies and required quantities.[7] It may omit manufacturing steps and shop-floor consumables, which are typically represented in a bill of process.
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