Your BOM Is a Living Document. Are You Treating It Like One?
By the CADPreview Team · Series: Hardware Visibility
"The BOM that left your machine last Thursday is already wrong. The question is how wrong, and whether anyone knows."
The schematic is done. You move to layout. Supply chain gets a BOM export.
That export is already a snapshot. The design is still moving. By the time quotes come back, the two have drifted apart in ways nobody is tracking.
The BOM Is Not a Document You Produce
Most teams treat the BOM as a deliverable. Something generated when the engineer decides it is ready, dropped into a shared folder, emailed across. That model positions supply chain as a downstream consumer waiting for engineering to throw something over the wall.
The better model: the BOM is a derivative of the schematic. Not a separate document. A view of the design, at a specific revision, from the angle that supply chain cares about. It does not need to be produced. It needs to be accessible.
Early Access Changes the Economics
The moment schematic capture is complete and the engineer moves into layout, the BOM is knowable. Every component, every value, every reference designator is already in the design. Supply chain does not need layout to be done.
If they can see a live BOM at schematic completion, costing runs in parallel with layout. The EOL flag gets raised while the engineer can still swap the part before the footprint is committed to copper. The sixteen week lead time surfaces before the schedule assumes eight. These conversations happen when the cost of changing something is low, not after the board is already in production.
The Revision Problem
Supply chain receives a BOM and starts working. Qualifications, alternates, pricing. Meanwhile the engineer makes changes. A capacitor gets derated. A connector variant changes. Nobody tells supply chain because there is no mechanism to tell them.
The BOM in their folder has no connection to the source. It does not update. It just sits there, becoming less accurate with every commit. The downstream cost is diffuse: quotes that do not match the board that gets built, alternates qualified for parts no longer in the design, EOL investigations opened on components already removed.
Access, Not Exports
Supply chain should be able to pull the BOM themselves, at any point, at any revision, without asking anyone. CADPreview connects directly to the KiCad project on GitHub. Supply chain gets a browser link. They pull the current BOM on any branch, at any tagged release, without installing anything, without emailing an engineer. When a component changes on Tuesday afternoon, they can see it on Tuesday afternoon.
The engineer adds nothing to their workflow. The exports stop. The snapshots stop diverging.
CADPreview is a web-based viewer for KiCad projects hosted on GitHub. Connect your repository once, share a link, and your whole team sees the current schematic, layout, and BOM in a browser, on any branch, at any release, without installing anything.