Part number, Properties and BOM types

If you’ve been exposed to Bill-of-Materials, you may already be familiar with the concepts of Part Number, Properties, and BOM types.  As a new openBoM user, those three concepts may be slightly different than what you may be familiar with.  Let’s explore each of these three concepts to ensure you understand how they are used in openBoM.

Part Number

A Part Number is the most fundamental “unit” in openBoM.  Everything in openBoM is identified by Part Numbers. Item (Part) has Part Number. In case you created BOM for a specific Item, BOM itself is identified by the same Part Number. Inventory (Part Catalog) has list of items. Each item is identified by Part Number. The following links provide you with further information:

  1. openBoM Fundamentals: Part Numbers
  2. How to manage Part Numbers in openBoM


BOM properties are additional attributes which can be added to a BOM.  Think of them as the header columns in a BOM spreadsheet.  Unlike mere column headers in a spreadsheet, BOM properties give you unparalleled flexibility customizing BOMs.  Properties can be public or private.  In addition, there are different types of properties, e.g., text, number, list, checkmark, reference, image, etc.  The following links provide you with further information on how to use BOM properties in openBoM:

Further information on BOM properties can also be found in the BOM Property section of the content page.

BOM types

openBoM works with four different types of what can be referred to as “BOM types”.  These are

  • Part lists: a BOM which represents all the parts collected from all assemblies and sub-assembly levels
  • Single level BOM: a BOM which is created from an assembly that is part of a CAD Top Level Assembly
  • Multi-level BOM: a BOM that creates a hierarchy of parts, assemblies, and sub-assemblies
  • Inventory (a parts catalog): a “BOM” that contains parts which can be assigned to a BOM

Here’s an example of a multi-level BOM in the openBoM multi-level BOM view.  Note: we continue to experiment on how to make multi-level BOMs as useful to you as possible.  Send us your feedback on

The following links provide you with further information about the different BOM types deployed by openBoM: