Quickly Updating Your BOM After Design Changes

Sjors de Wit

June 3, 2019

Last updated: Nov 17, 2020

Updating the Bill Of Materials manually is tedious and error-prone, especially for PCB designs with many different components. The alternative is exporting a new BOM after every design change. The downside is that you will lose all manual edits, such as formatting or pricing information.

Our solution

We use KiCad for our PCB design. Fortunately, Kicad supports scripting in python. We have developed a custom BOM script that can create/update excel spreadsheets. This provides us with a number of benefits:

• No more mistakes: the BOM is always correct.
• Save a lot of time spent on boring manual tasks.
• Easy to generate a BOM during the design (e.g. for cost estimation).
• Quickly verify the BOM is up to date.

The script does not silently update the spreadsheet, it highlights all changes it makes. You can then verify whether everything is as expected:

• Changed fields are highlighted in yellow
• New lines are highlighted in green: you may want to add e.g. pricing info.
• Proposed deletes are highlighted in red: you may want to delete these.

When you finish reviewing the updated BOM, simply remove the highlights.

Open source

Our KiCad BOM Sync script is open-source and available on Github.