Design variants and the BOM

A KiCad design can define several assembly variants, for example a Lite and a Pro population of the same board. Prism lets you pick a variant and see the schematic, board, 3D model and BOM as that variant is built.

The screenshots on this page use USB-PD-Trigger-Board’s 20V variant, which leaves out the USB Type-C connector, J1.

Choose a variant

When the revision you are viewing defines variants, the Visualizers toolbar shows a Variant menu.

Open the project’s Visualizers.
In Variant, pick a variant. Default is the base design.

The choice applies to the Schematic and PCB viewers, open insets, the 3D model, the BOM, the Selection panel and the design search.

The Schematic tab with the 20V variant picked in the Variant menu: the Type-C connector J1 is crossed out as not fitted

The variant is saved in the page URL as ?variant=<name>. A link you copy opens the same variant, and reloading or going back keeps it.

If the revision has no variants, the menu does not appear. Other states show a note next to the menu:

Variant “…” is not in this revision; showing the default assembly. The link names a variant this revision does not have. The link is left as it is, so it still works on a revision that has the variant.
This revision has no variant data; showing the default assembly.
Design variants could not be loaded. Select Retry.

See the parts that are not fitted

The 3D model hides parts that are marked do-not-populate (DNP) in the selected variant. Select Show DNP above the model to show them without changing the variant.

The 3D model with the 20V variant: J1, the USB Type-C connector, is not drawn

The same view with Show DNP on: J1 is drawn again and the button reads Showing DNP

Some limits apply:

DNP set on a KiCad rule area is not applied to the parts inside it. DNP set on a part or a sheet is applied.
A part with alternate footprints stays visible in 3D with its DNP state unresolved. The 3D tab names how many such parts there are, for example 2 alternate-footprint parts stay visible.
The Assembly Assistant tab is generated for the base design and does not follow the selected variant. It says so when a variant is selected.

Read the BOM

The BOM tab lists the parts of the revision, grouped into rows of identical parts, with a column per field. A column whose value differs between the parts in a row reads Mixed, for example DNP when the selected variant leaves out some of them.

The BOM tab for the 20V variant: the search box, the All components and Assembly filters with their counts, and rows grouped by value with references, DNP (No or Mixed) and In BOM flags and descriptions

Filter. Type in Search references and fields… to filter by reference or any field. Prefixes match as you type; add a trailing space to match a reference exactly. You can narrow to one field with ref:, value:, mfr:, mpn:, vendor: or footprint:, for example value:10k.
Assembly filter. All components lists every part with its effective In BOM and DNP flags. Assembly keeps only the parts that are fitted: in the BOM and not DNP. The counts next to the filter show how many parts each choice includes.
Cross-probe. Select a row to select its parts on the schematic and the board.
Columns. Drag a column edge to resize it; Reset columns restores the widths.

The BOM never drops a part: a part that is excluded or not fitted in the selected variant stays in All components with its flags.

If the revision’s part data is not ready, the tab shows BOM metadata is not available; see Design data.

Variants in a release

Release Studio offers the same variants when you start a release, with Default first. The variant you pick is recorded as part of the release. See Release Studio.

Compare BOMs between revisions

To see how the BOM changed between two commits, use the BOM tab of Design Comparison.