What are Bill of Materials (BOM)?

Bill of Materials (BOM) Definition

A bill of materials (BOM) is a comprehensive list of parts, items, assemblies, sub-assemblies, intermediate assemblies and other materials required to create a product, as well as instructions required for gathering and using the required materials. A BOM can be thought of as the recipe and shopping list for the creation of a product, presented in a hierarchical format. The bill of materials explains what, how, and where to buy required materials, and includes instructions for how to assemble the product from the various parts ordered.

Bill of Materials illustration

Related Terms

  • Engineering Bill of Materials
  • Manufacturing Bill of Materials
  • Single-level BOM
  • Multi-level BOM
  • Top-level BOM