Production is a process of combining various material inputs and immaterial inputs (plans, know-how) in order to make something for consumption (the output). It is the act of creating output, a good or service which has value and contributes to the utility of individuals.
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.
Simply put, the bill of materials or most often called as BOM is a list of parts, components, sub-assemblies and assemblies required in developing the product. The BOM is always core for any manufacturing process as it provides all the information required to build the product.