What is an Engineering Bill of Materials (EBOM)?

The engineering bill of materials (EBOM) is a special type of bill of material that defines the product as designed. It contains the list of items, parts, components, subassemblies, and assemblies in the product designed by engineering.

The engineering BOM is typically created by engineers using computer-aided design (CAD) or Electronic Design Automation (EDA). And for any given product design more than one EBOM may be created. For example, the BOM for the Printed Circuit Board Assembly (PCBA) designed by an electrical engineer lists the resistors, capacitors, and chips. The BOM for the product as designed by a mechanical engineer includes custom parts and purchased hardware like an LCD, buttons, and screws.

While multiple engineering BOMs may exist, the EBOM is not the only type of bill of material. The engineering bill of materials (EBOM) deals with how a product is designed, while the manufacturing BOM or MBOM details what is needed to assemble a product and differs from the EBOM in both structure and depth.

How an engineering BOM helps

Manufacturing a product is often compared to that of a recipe. If you miss an ingredient or step in the baking process the outcome will likely be a complete failure. With an engineering BOM, missing a part or component will negatively impact manufacturing the product without any hiccups. Because the information captured in an EBOM is handed-off to manufacturing, the completeness – or lack thereof – could influence the product quality.

Three reasons a complete and accurate EBOM supports manufacturing and company success

Capturing the right level of detail in an engineering BOM can prepare the company for success and prevent needless extra work for engineering, manufacturing, sourcing, and purchasing in the long run. A complete and accurate engineering BOM can better prepare manufacturing for production runs and supports the new product introduction (NPI) process along the way.

Here are three reasons to document the details:

1. Got good parts?

   It is good manufacturing practice to verify the first article parts coming off a new tool. With a comprehensive bill of materials, manufacturing will have adequate information to ramp tools for new parts and time to test parts before production fully ramps.

2. Best lead time and pricing.

   Give manufacturing the right parts and right quantities and they are armed with the information to make better purchasing decisions. They can negotiate with multiple vendors to obtain the most competitive pricing. Getting them the information early in the process also ensures that parts with long lead times are ordered and delivered when they need to be without expediting charges.

3. Prevent extra revision cycles and work.

   The manufacturing department must operate with efficient processes and if they’re handed the correct and complete details on the parts, items, and components they won’t be left second-guessing. With the right level of detail in the EBOM, extra and unnecessary changes in the manufacturing process can be avoided.

Three setbacks of an incorrect and incomplete engineering BOM

Manufacturing products with the wrong components specified in the engineering BOM will create accuracy, interoperability, and production issues ultimately. Here are just three setbacks you will experience if you have incorrect EBOMs.

1. Build problems.

   If the number of components isn’t correctly listed in an EBOM (for example, 10 screws are documented but your product requires 12), procurement teams will not have the necessary information to buy the right quantities to fulfill customer demand. Insufficient inventory will lead to production line stoppages and the inability to meet production schedules.

2. Time and money down the drain.

   Any incorrect component or subassembly defined in the EBOM may result in having unusable inventory and/or production delays while the correct parts are ordered.

3. Out of control revision cycles.

   In order to get the product built and shipped to customers, a smooth hand-off from engineering to manufacturing is essential. Additional change cycles will ensue whenever a given EBOM is not correctly documented and transferred to production teams and systems.

Engineering BOM—Why it’s best to get it right, right from the start

Engineers are often asked to release designs earlier and even before they are completely ready. They must work hard to pass the right and correct information to manufacturing so their design can become a reality. With a complete and accurate engineering bill of materials, the hand-off to manufacturing will be made much smoother. Manufacturing and supply chain teams will be armed with the information to make better decisions, including pricing and lead time options, as well as manufacturing process and logistics choices.

Effective BOM management implementations streamline product assembly by integrating with ERP systems, enhancing collaboration, reducing errors, and improving manufacturing efficiency. Investing in cloud-based BOM management ensures traceability, version control, and compliance, leading to optimized production and faster time to market. When all the details including parts, items, components, and quantities are correctly detailed in an EBOM—disruptive last-minute changes can be avoided.

Arena PLM helps manage and control EBOMs.

Arena PLM helps engineering, manufacturing, supply chain partners, and affected teams better control their product record, BOMs, and change management processes. All bill of materials (engineering BOMs and manufacturing BOMs) and product information is stored in a single source of truth allowing all stakeholders easy, controlled access via the cloud. Ensuring that teams can streamline new product development (NPD) and new product introduction (NPI) processes is further enhanced with business-ready integrations. Arena PLM integrates with MCAD, EDA, ERP, CRM, and other applications eliminating duplicate data entry and ensuring that your product information is accurate as it passes from upstream systems to downstream ones. Check out the free BOM template in Excel or PDF.