{"id":20623,"date":"2026-03-13T16:48:25","date_gmt":"2026-03-13T20:48:25","guid":{"rendered":"https:\/\/blogs.sw.siemens.com\/teamcenter\/?p=20623"},"modified":"2026-03-26T09:05:10","modified_gmt":"2026-03-26T13:05:10","slug":"assembly-bom-vs-usage-bom","status":"publish","type":"post","link":"https:\/\/blogs.sw.siemens.com\/teamcenter\/assembly-bom-vs-usage-bom\/","title":{"rendered":"Assembly BOM versus Usage BOM"},"content":{"rendered":"\n

\u27a1\ufe0f Making the right choice for modern product development<\/h3>\n\n\n\n

As products become more complex and teams more distributed, the way organizations manage their Bill of Materials (BOM)<\/a> is evolving. Teamcenter\u2019s<\/a> new Usage BOM capability, introduced in the 2512 release, marks a significant shift in how companies can structure, collaborate on, and control their product data. <\/p>\n\n\n\n

But what does this mean for your business, and how does Usage BOM compare to the traditional Assembly BOM approach?<\/em><\/p>\n\n\n\n

Let\u2019s explore the differences, benefits, and practical considerations, so you can make the right choice for your organization.<\/p>\n\n\n\n

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\ud83d\udcad Understanding the two models<\/strong><\/h3>\n\n\n\n

Assembly BOM<\/strong> has long been the standard for managing product structures. In this model, the BOM is tightly linked to assembly revisions. Every change, whether it\u2019s adding a new part, updating a property, or modifying a quantity, requires a new revision of the assembly. This approach works well for products with low variability and where a single engineer or author manages the BOM, often directly from CAD tools.<\/p>\n\n\n\n

Usage BOM<\/strong>, on the other hand, introduces a more flexible, occurrence-centric approach. Instead of tying every change to a new assembly revision, Usage BOM allows each part usage (or occurrence) to be managed independently. Multiple engineers can collaborate on the same BOM at the same time, making changes in parallel and tracking updates at a granular level. This is especially powerful for organizations dealing with high product variability, frequent changes, or the need for regional customization.<\/p>\n\n\n\n

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\ud83d\udd01 Collaboration and change management<\/strong><\/h3>\n\n\n\n

One of the most significant advantages of Usage BOM is its support for true cross-functional collaboration. In the Assembly BOM model, changes are sequential and often require locking the structure, which can slow down development and create bottlenecks. Usage BOM removes these barriers by enabling concurrent editing. Engineers, manufacturing planners, and service teams can all work on the BOM simultaneously, seeing each other\u2019s changes<\/a> in real time.<\/p>\n\n\n\n

This parallelism means that multiple Engineering Change Notices (ECNs) can be processed at once, without waiting for one change to finish before starting another. Occurrence-level change tracking also simplifies out-of-sequence revisions, making it easier to manage complex products and fast-moving development cycles.<\/p>\n\n\n\n

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\ud83e\udd68 Flexibility for complex products<\/strong><\/h3>\n\n\n\n

Modern products are rarely static. They\u2019re built in multiple variants<\/a>, customized for different regions, and updated frequently to meet market demands. Usage BOM is designed for this reality. It supports full effectivity\u2014by date, unit, or milestone\u2014so you can manage when and where each part is used. Regional customization, modular kits, and service-specific parts are all natively supported.<\/p>\n\n\n\n

For example, if you need to add a service-only part that\u2019s relevant in one region but not another, Usage BOM lets you do this without disrupting the integrity of the overall BOM. Service teams can plan concurrently, and manufacturing engineers can restructure plant BOMs for localization, all within the same collaborative environment.<\/p>\n\n\n\n

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\ud83d\udc68\u200d\ud83d\udd27 Downstream impact: MBOM and SBOM<\/strong><\/h3>\n\n\n\n

The benefits of Usage BOM extend beyond engineering<\/a>. In manufacturing<\/a>, Usage BOM enables fine-grained change control, improved plant BOM management, and better change propagation. Changes can span across revisions without duplication, supporting global manufacturing and complex effectivity needs.<\/p>\n\n\n\n

In service<\/a>, Usage BOM allows for occurrence-level control, regional effectivity, and the addition of service-only parts visible only in the service view. Multiple service teams can plan concurrently, improving service accuracy, accelerating response to field changes, and enhancing compliance.<\/p>\n\n\n\n

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\ud83e\udd14 When to choose each model<\/strong><\/h3>\n\n\n\n

So, which BOM model is right for you? Here are some practical guidelines:<\/p>\n\n\n\n