Carsten Froehlich 07/19/2023

What are CAD BOM, EBOM, MBOM, and SBOM?

Guest Post by Carsten Froehlich (Sales Executive, Siemens Digital Industries Software)

What are CAD BOM, EBOM, MBOM, and SBOM?

Efficient management of bill of materials (BOM) is crucial in product development and the manufacturing industry. BOMs are used to organize the various components and assemblies of a product and define their relationships. They enable a precise representation of the product structure and support planning, development, manufacturing, maintenance, and service of products. In this article, we will delve into some important BOM concepts: CAD BOM, EBOM, MBOM, and SBOM. We will explore how these BOMs work together and the role they play in different phases of the product lifecycle.


The CAD BOM (Computer-Aided Design Bill of Materials) is closely associated with the 3D CAD model of a product. It contains a detailed list of all the components and assemblies used in the virtual design. The CAD BOM allows for precise visualization and analysis of the product structure and supports the verification of design aspects such as fit, collisions, and material efficiency. It also serves as the basis for generating other BOMs such as EBOM and MBOM.


The EBOM (Engineering Bill of Materials) is a BOM that reflects the product development process. It includes all the relevant components, assemblies, and materials needed for the design and functionality of a product. Engineers create the EBOM, which serves as the foundation for development documentation, design changes, and collaboration among various departments, including design, development, and procurement.


The MBOM (Manufacturing Bill of Materials) is a BOM specifically created for manufacturing. It contains all the components, assemblies, and materials required to produce a product. The MBOM provides detailed information about BOM structure, quantities, workstations, manufacturing processes, and other relevant manufacturing information. It forms the basis for the entire manufacturing process and supports material procurement, work planning, and resource allocation.


The SBOM (Service Bill of Materials) is a BOM used for service and maintenance of products. It contains information about the individual components and assemblies needed for repair, replacement, or maintenance of a product. The SBOM supports efficient planning of service tasks, availability of spare parts, and documentation of service processes.

These different BOMs serve different purposes but are closely interconnected and complement each other. They facilitate the smooth flow of the entire product lifecycle, from conceptualization and development to manufacturing, service, and maintenance.

In summary, CAD BOM, EBOM, MBOM, and SBOM play a crucial role in successful product development and manufacturing. They form a seamless information chain that enables different departments to collaborate efficiently and ensure the product meets requirements. By utilizing these BOMs, companies can save time and resources, reduce errors, and ultimately enhance customer satisfaction. Thorough understanding of these concepts is therefore essential for companies in today's competitive industry.