An engineering bill of materials (EBOM) is a product recipe structured from the design standpoint, rather than the manufacturing standpoint. It originates in software used by the engineering department, such as computer-aided design (CAD) or electronic design automation (EDA). The engineering bill of materials provides the components and directions to make a given product and includes things like raw materials, items, parts, subassemblies, interrelated data layers, as well as other factors, such as those that contribute to the cost of the product.
The engineering bill of materials focuses on parts as they exist in the design sense, and typically lists items from the engineering perspective, for example, on an assembly drawing. It does not include things like packaging, shipping containers and other components needed for a shippable product, or specify how parts should be grouped at each stage or production. Such items are instead typically included in the manufacturing bill of materials (MBOM).An accurate engineering bill of materials is critical since the manufacturing bill of materials is based on the EBOM. Inaccuracy or incompleteness can mean incorrect product costs, inventory levels, and accounting; production problems and delays; unnecessary revision cycles; and other issues. The right level of detail gives manufacturing information it needs to plan for new tools and testing, enables better part-purchasing decisions and prevents unnecessary changes.
Aligning bills of materials is so important that many in the field recommend that companies work toward a single bill of materials.
The engineering bill of materials is often managed in product lifecycle management (PLM) software.