Take Control of Your Bill of Materials

A Bill of Materials is a comprehensive list of all the raw materials, components, assemblies and subassemblies, along with instructions, that go into the manufacture, assembly or repair of a product.

Using a hierarchical structure, a BOM provides detailed information about every part and step required to create the final product, with the finished product at the top and the individual components and raw materials populating the bottom levels.

Key elements of a BOM include:

• Part identifiers, such as a name or number
• Descriptions – brief explanations of a part or assembly that reinforce identification, such as size
• Quantities
• Unit of measure
• BOM level – usually a unique number indicating where each part or assembly fits in relation to other assemblies and the final product
• Routing – indicates at which point in the manufacturing process the material is needed
• Procurement type - indicates whether a component is to be purchased, produced internally or manufactured by a third party

The most common types of BOMs include:

Engineering Bill of Materials (EBOM)

EBOMs are created during the product design phase and include detailed engineering specifications for parts, components and subassemblies, technical drawings and instructions developed by product engineers.

Manufacturing Bill of Materials (MBOM)

MBOMs focus on product production, identifying all of the parts and assemblies for a particular product and specifying how materials are to be assembled. These BOMs cover every aspect of production necessary to build and ship a product, including packaging.

An MBOM is also important in that it identifies what parts are needed at each stage of production, helping manufacturers better manage the purchase and delivery dates of raw materials, and ultimately the final product.

Service Bill of Materials

A service BOM is often created during a product’s engineering phase. It lists the replaceable parts and instructions for product maintenance. It is used for servicing and repairing products.

Single-Level BOM and Multilevel BOM

BOMs can be structured as single-level or multilevel, depending on the complexity of the product and the manufacturing process.

A single-level BOM provides a straightforward list of components needed to create a product. It does not account for subassemblies or hierarchical relationships between components. It is best for simple products with few components.

A multilevel BOM includes all components and their hierarchical relationships, detailing subassemblies and how they contribute to the final product. Each subassembly has its own BOM nested within the main BOM. Multilevel BOMs are used for complex products with multiple assemblies, such as a vehicle.

Bill of Materials software automates the creation and use of BOMs, decreasing errors and making it easier to initiate changes and reworks. BOM software avoids manual processes associated with spreadsheets, helping to prevent inconsistencies, duplications and omissions that may result in production delays and wasted resources.

Bill of Materials software not only creates major efficiencies in design and production processes, it also enables greater accuracy and control. With it, manufacturers can automate data entry and document updates, which can then automatically populate across the system.

BOM software centralizes all BOM information, promoting better collaboration and ensuring team members are working with the latest and most accurate information. Businesses get automatic full traceability for easier regulatory compliance. As operations grow, BOM software can handle increasing complexity, including multilevel BOMs able to identify and track thousands of components.