Bill of Materials

A Bill of Materials, also known as a BOM, is a list of the raw materials, sub-assemblies, intermediate assemblies, sub-components, components, parts and the quantities of each needed to manufacture a finished good.

A BOM can define products as they are designed (engineering bill of materials), as they are ordered (sales bill of materials), as they are built (manufacturing bill of materials), or as they are maintained (service bill of materials).

Bill of material can be defined in two levels.

  • Single level BOM - displays the assembly or sub-assembly with only one level of children.

  • Multilevel BOM - displays the assembly or sub-assembly with more than one level of children.

Engineering Bill of materials

An engineering bill of materials (EBOM) reflects the product as designed by engineering, referred to as the 'as-designed' bill of materials. The EBOM is not related to modular BOM or configurable BOM (CBOM) concepts, as modular and configurable BOMs are used to reflect selection of items to create saleable end-products.

The EBOM concept aligns to sales BOMs (as sold), service BOMs (as changed based on changes due to field service). This BOM includes all substitute and alternate part numbers, and includes parts that are contained in drawing notes.

Configurable Bill Of Materials

A configurable bill of materials (CBOM) is a used by industries that have multiple options and highly configurable products, such as telecom systems, data-center hardware (SANS, servers, etc.), and PCs.

The CBOM is used to dynamically create 'end-items' that a company sells. The benefit of using CBOM structure is it reduces the work-effort required to maintain product structures.

The configurable BOM is most frequently driven by 'configurator' software. However it can also be enabled manually.

Note that manual maintenance is infrequent because it is unwieldy to manage the number of permutations and combinations of possible configurations.

While most configurators use top-down hierarchical rules syntax to find appropriate modular BOMs, maintenance of very similar BOMs becomes highly excessive.

A newer approach, (Bottom-Up/Rules-Based Structuring) utilizing a proprietary search engine scheme traversing through selectable componentry at high speeds eliminates the Planning Modular BOM duplications.

The search engine is also used for all combinatorial feature constraints and GUI representations to support specification selections.

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