Bill of Material (BOM)

A bill of materials sometimes bill of material or BOM is considered as a structured list for an object (semi-finished or finished product) that contains the list of the raw materials, sub-assemblies, intermediate assemblies, sub-components, components, parts with the name, reference number, quantity, and unit of measure of each component.

The Bill of material is required by a contractor to complete a contract, or by a supplier or vendor to complete an order. A bill of material can only refer to a quantity greater than or equal to one of an object.

A BOM can be demonstrated in the following formats:
A single-level BOM – This kind of BOM shows the assembly or sub-assembly with only one level of children. Thus it exhibits the components required directly to create the assembly or sub-assembly.

An indented BOM - This kind of BOM shows the highest-level item nearby to the left margin and the components utilized in that item shifted more to the right.

Generally there are two types of bills of materials available for a product engineering and manufacturing BOM. The engineering BOM usually records items in accordance with their relationships with parent product as characterized on assembly drawings. But this is not enough to neither demonstrate the grouping of parts at each stage of the production procedure nor contain all of the data required to support manufacturing or procurement. These requirements lead to compel the arrangement of the product structure to be dissimilar so as to guarantee manufacturability. Thus, engineering and manufacturing will include the different valid views for the same product.

Theoretically, the BOM is created mechanically by the CAD system but in reality there is generally human interference or even re-entry.

The following information is visible in a bill of materials:
• Header (Product or Higher-Level Assembly)
o Product/Assembly Item Number
o Product/Assembly Name
o Product/Assembly Description
o Unit of Measure
o Revision Level
• Each Component/Item
o Item Number
o Item Name
o Item Description
o Revision Level
o Unit of Measure
o Quantity per (each higher level assembly)
o Effectivity (date in and date out or serial number in and serial number out)

Posted by Rajib Dey
Business Development
Global Associates
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