OpenBOM — fundamentals of working with Bill of Materials and Part Catalogs

Working with BOM and Part Catalogs is one of the topics that often raises questions. OpenBOM provides a very flexible mechanism allow to define Bill of Materials, Part, and connects information about how Parts are used in different Bill of Materials.

The idea of Part Catalog in OpenBOM is to provide a centralized storage for all information about Parts (both standard and custom), so this information can be used in different BOMs.

You can think about BOMs and Parts in the following way:

Although use of Part Catalogs is a very powerful option, you might decide to create BOM without usage of Parts defined in a catalog. It is a very useful option for quick import of BOMs from your existing Excel spreadsheets, import BOM from any CAD system, etc.

So, how OpenBOM data model will look like in this case? It will be very simple, like you can imagine it in Excel — each part will be stored in the same BOM table with corresponding attributes.

You can see it from the picture. Even you defined the same Part Number (PN10) in both BOMs (BOM1 and BOM2) the information about this PN10 will be duplicated and you will require to manually update this information in both places. This is a price for simplicity to create BOM without Part Catalog option. Sometimes, it worth doing so (for simple projects, CAD integrations, etc.) or it can be a first step to transform your BOMs from spreadsheets to OpenBOM.

Create and Edit BOM in OpenBOM without Part Catalog

To edit BOM, add properties and enter information in OpenBOM without Part Catalog is simple — this is a default option. When you create a BOM in OpenBOM, it created without assigned Part Catalog. Use “Create New BOM” command

Here is a screenshot of a new BOM:

Create and Edit BOM in OpenBOM with Part Catalog

To start using BOM with Part Catalog, you need to create it (Part Catalog) first. You can use Create New Catalog command from the menu. You can define as many Part Catalogs as you want. Name of Part Catalog really doesn’t matter — it is only used to assign Part Catalog to BOM. You can use multiple catalogs with the same BOM. You can think about Part Catalogs as libraries. Part Catalogs can be shared between users and teams.

Here is a screenshot of a simple Part Catalog with 2 parts I created:

Once you created Part Catalog, you can use it in a BOM by selecting via Part and Catalogs menu button in BOM:

Once you done with this, Part Number property in BOM automatically gives you a list of all available Part Numbers from all Part Catalogs associated with this BOM (note: we are currently allow to search only by Part Number, but better options to search is coming. Tip — you can use OpenBOM Part Search to find any part in OpenBOM now — navigate to this search via dashboard).

Properties with grey background are properties automatically retrieved from Part Catalog. You can ask a question- what if I defined property in BOM (eg. Description first ) and then assigned Part Catalog to BOM? Will OpenBOM automatically detect Description property? The answer is unfortunately — not yet. We are working to improve Part Catalog assignment process. But for the moment, you need to delete all properties from BOM that you want to manage via Part Catalogs. We are also working on a better way to indicate Part Catalog vs BOM properties in user interface.

After a specific Part Number is selected, OpenBOM retrieves the data from Part Catalog

Some future development notes — we’re planning to provide some tools automatically creating Part Catalog item from BOM properties. It will make transition from simple Excel imported to OpenBOM to BOM with Part Catalog simpler. Today, you can do it in 2 steps- (1) import Part Catalog ; (2) Import BOM, delete not needed properties and assign previously imported Part Catalog.


OpenBOM provides powerful out of the box functionality to create BOMs and Manage Part Catalogs. You can start using it in a minute. The option to manage BOMs without Part Catalog is an important element of OpenBOM flexibility. The ramp up time of working with OpenBOM is minutes. You can start using it right away without worry too much about organizing all Parts in Catalogs. You can always do it later and switch to more advanced option. BOM and Part Catalogs option is robust and flexible allows you to mange Part lifecycle independent from BOM and organize central part management using OpenBOM. Unique Part Catalog sharing option (I will talk about it in my future blogs will help organize distributed catalogs between contractors, suppliers and teams.

If you have questions, please reach me out via oleg @ openbom dot com.

Best, Oleg