Multi-level (or nested) BOMs usually raise many questions with users. In this article, I want to discuss how openBOM handles multi-level BOMs. And please keep in mind, we’re still working to improve how we handle multi-level BOMs. With that in mind, I’ll also share what multi-level related features we are still working on and what you can expect to be delivered in the near future. As I mentioned in the openBoM fundamentals (1) article , the simplest BOM is a list of parts. Each BOM contain [and can be assigned] Part Numbers; this is how you can identify items in openBoM.
By using Part Numbers in a BOM you can connect multiple BOMs together (nested levels) and it allows you to define multi-level BOM model. The Part Numbers in the BOM below correspond to sub-assemblies.
Let’s now transition to Multi-level BOM navigation. The simplest, but not the most useful navigation of a multi-level BOM is using the “Composed of” button located in a BOM view. By clicking this button, you will navigate to the lower level BOM of a selected Part (if that Part happens to be assigned to a separate BOM). Otherwise, a “No nested BOM” message will appear. Our navigation to an upper level BOM is not useful at the moment; we are working to improve it. The pic below shows where the “Composed of” button is located. When clicked, in this example, it will navigate you to the sub-assembly with the Part Number 5400-CB assigned to it.
The Multi-level BOM view is a separate view available today as a Dashboard icon.
Although the multi-level BOM view is a separate view from the default single level BOM view, we are planning to improve this with future releases where single and multi-level views will be better integrated together and easier to navigate. With a multi-level BOM view, you can navigate between branches designated with a “+” in front of a number on the far left of the multi-level BOM. Note: Currently only one branch can be opened at a time.
Also, and important to mention, when you first open a multi-level BOM view, you will see the configuration screen.
The configuration screen allows you to select the attributes (properties) which will be visible in the BOM view. You can also view property information by clicking the “Info panel” button for any given item appearing in the BOM.
Each separate BOM level in openBOM can have a slightly different set of attributes as when there’s a combination of multidisciplinary BOMs, e.g., mechanical, electrical, PCB and even software. A multi-level BOM view will provide a unified view of all data with a consistent set of attributes. For example, in the pic below, the sub-assembly 5500-EEE comes from an eBOM added to the top-level-BOM.
Here are simple examples illustrating the two methods for creating a multi-level BOM. (1) By using Part Numbers via a few manual steps:
And (2), generating a multi-level BOM from a CAD system:
Only the Onshape integrated openBOM app can generate a multi-level BOM at the moment. Our plug-ins for other CAD systems will gradually be updated later this year to support true multi-level BOM generation and viewing.
Oleg, 17 May 2017