BOM Management: The Need for Separate Design, Engineering, and Manufacturing BOMs
Blog Article | November 13, 2024
Effective management of a Bill of Materials (BOM) is crucial for companies involved in product development, manufacturing, and lifecycle management. BOMs serve as the backbone of product data, ensuring that every part, assembly, and component is properly accounted for. However, different departments, such as design, engineering, and manufacturing, require different types of BOMs, tailored to their specific needs. This blog will explore why it's essential to maintain separate BOMs—CAD BOM, EBOM, and MBOM—and how tools like Teamcenter help streamline BOM management in complex product environments
What Are the Different BOMs?
To better understand the need for separate BOMs, we can look at the flow and structure of the CAD BOM, EBOM, and MBOM.
CAD BOM (Computer-Aided Design Bill of Materials)
The CAD BOM represents the design of the product, typically showing how parts fit together in a top-down, hierarchical structure with subassemblies beneath main assemblies.
EBOM (Engineering Bill of Materials)
The EBOM goes beyond just the mechanical parts found in the CAD BOM. It is often organized by partitions such as chassis, engine, or hydraulics, and includes non-CAD components like electrical and software elements. This provides a complete view of the product’s systems, offering a more comprehensive understanding of the engineering requirements.
MBOM (Manufacturing Bill of Materials)
The MBOM is structured based on the manufacturing process. It is organized by plant, line, area, and station, with each station including a bill of equipment and bill of process, specifying the parts needed and the work instructions for assembly. The MBOM ensures that the manufacturing process is clearly mapped out, from equipment to the individual parts required at each stage.
Below is an illustration that shows how the CAD BOM flows into the EBOM and then into the MBOM, highlighting the organizational differences and the interconnected nature of these BOMs throughout the product lifecycle:
This graph demonstrates how each BOM is aligned while allowing for flexibility. For example, the CAD BOM focuses on the design, the EBOM partitions the product into systems and includes all relevant components (software, mechanical, electrical), and the MBOM is organized by the manufacturing process to ensure smooth production. This alignment ensures that each team has the information they need while maintaining consistency across the lifecycle of the product.
CAD BOM/EBOM/MBOM in Product Lifecycle Management
BOMs are integral to every stage of product lifecycle management (PLM), ensuring that all aspects of product design, development, and manufacturing are aligned. However, the purpose and focus of each BOM vary, which is why keeping them separate is essential.
CAD BOM
CAD BOM is a tool primarily used in the design phase, capturing the structural elements of the product. Designers rely on CAD BOMs to validate the form, fit, and function of a product before passing it to engineering.
EBOM
EBOM bridges the gap between design and engineering. It captures engineering decisions about the product's performance, materials, and compliance with standards. The EBOM helps engineers ensure the product meets all necessary specifications.
MBOM
MBOM provides a blueprint for how the product will be manufactured. Manufacturing teams rely on MBOMs to determine the resources, processes, and timelines needed to create the product efficiently.
Together, these BOMs ensure that each stage of product development has the appropriate data needed to carry out its role effectively. By separating them, each department can work independently while ensuring consistency across the product lifecycle.
Limitations of Using a Combined System
While it may seem efficient to maintain a single BOM for all departments, this approach introduces several limitations:
Compromises Made
A combined BOM forces design, engineering, and manufacturing teams to share a single source of data, which often leads to compromises. For instance, design-related data might clutter the BOM, making it difficult for manufacturing teams to find relevant information, and vice versa.
Impact of Making Changes
In a combined system, any change made by one department affects the entire BOM. For example, a design change might unintentionally disrupt the manufacturing process or vice versa. This lack of compartmentalization increases the risk of errors and miscommunication.
Timing Affected
The timing of changes and updates becomes challenging when all departments are working from the same BOM. If design or engineering updates occur after manufacturing has begun, it can lead to costly production delays and rework.
Benefits of Separate BOMs
Maintaining separate BOMs offers numerous advantages, including greater flexibility, revision control, and the ability to meet specific departmental needs.
Revision & Structure Independence
Each BOM can evolve independently, allowing for greater flexibility. Design, engineering, and manufacturing can make revisions without affecting one another, ensuring that each department works with the most relevant and up-to-date information.
Flexibility in Management
Separate BOMs allow each team to manage their own data while still ensuring overall product alignment. Engineering teams can focus on materials and tolerances, while manufacturing teams concentrate on assembly and production processes.
Key Drivers for BOM Separation
Factors such as the complexity of the product, the number of parts, and the involvement of multiple departments all drive the need for BOM separation. For example, an aerospace manufacturer may require separate BOMs to ensure that each component meets stringent regulatory requirements at every stage of development.
Different Use Cases
Separate BOMs also provide tailored solutions for specific use cases. For instance, design teams can focus on creating a visually accurate model, while manufacturing teams can use a simplified BOM that includes only the parts needed for production.
Using Teamcenter to Keep Separate BOMs
Teamcenter provides powerful capabilities to ensure that your CAD BOM, EBOM, and MBOM remain aligned throughout the product lifecycle. By separating these BOMs, Teamcenter allows flexibility in how you manage and revise each one, while ensuring that they remain interconnected. Whether you're making changes to the EBOM or adjusting the MBOM for production, Teamcenter offers tools to maintain synchronization between them, avoiding costly errors or miscommunication between design and manufacturing teams.
To illustrate how these capabilities evolve, below is the Enterprise BOM Roadmap, showcasing the planned enhancements in BOM management through 2024. This roadmap highlights the transition from global MBOM creation to more specific plant-level BOMs, along with integrated process planning and change management features:
This roadmap demonstrates Siemens' continued investment in tools like Teamcenter to support BOM management for engineering and manufacturing companies, ensuring that your processes remain up to date with the latest advancements in BOM technology.
Case Studies and Industry Example
At Saratech, we’ve seen the impact of separate BOMs through our work with Our Next Energy (ONE), an electric vehicle technology company. Initially using a basic PLM solution, ONE faced challenges managing complex data across design, engineering, and manufacturing. With our help, they transitioned to Siemens’ PLM tools, implementing separate BOMs for different teams.
This shift allowed each department to work independently while maintaining alignment, improving efficiency and speeding up their development process. The integration of Teamcenter with their ERP system also streamlined supply chain operations, driving faster innovation and better collaboration.
Conclusion
Managing separate BOMs for design, engineering, and manufacturing is essential for companies seeking to optimize their product development processes. Tools like Siemens Teamcenter make this task more manageable by providing a flexible, collaborative platform. With separate BOMs, teams can focus on their specific needs while maintaining alignment across the product lifecycle. By doing so, companies can improve efficiency, reduce errors, and streamline the path from design to manufacturing.
