A
bill of materials or
product structure (sometimes
bill of material,
BOM or
associated list) is a list of the raw materials, sub-assemblies, intermediate assemblies, sub-components, parts and the quantities of each needed to manufacture an
end product. A BOM may be used for communication between manufacturing partners, or confined to a single manufacturing plant. A bill of materials is often tied to a
production order whose issuance may generate reservations for components in the bill of materials that are in stock and
requisitions for components that are not in stock.