A good definition of Bill of materials comes from wikipediaBill of materials (BOM) is a list of the raw materials, sub-assemblies, intermediate assemblies, sub-components, components, parts and the quantities of each needed to manufacture an end item or final product.All products have bill of material from engineering bill of materials, manufacturing bill of materials and service bill of materials.
When you are required to estimate the time to manufacture a finished product you must take into account the bill of material of the finished product.Bills of materials for quoting and cost estimating can be broken down into 3 categories.
The first category is raw material.
Raw material are those bill of material items that are the building blocks to create a finished or final product.
This would include items such as wood, sheets of metal, coils, wire, plastic, rubber, etc.
These type off bills of materials are usually some sort of commodity, especially when you get into sheet metal, wood, etc.