Catching the Error Before the Board Ships

By Bil Herd  ·  MCG LLC

The most expensive mistakes in hardware are the ones that reach the fab or the assembly line. A single wrong part, a rotated footprint, a BOM line that does not match the schematic, and a build turns into a scrap pile and a schedule slip. Almost every one of those errors is catchable beforehand. The problem was never whether you could catch them. It was whether you could afford the hours to check everything, every time.

What cross-checking actually means

Cross-checking is the discipline of verifying every artifact in a design against a primary source instead of against memory or assumption. In practice that means:

• The schematic against the datasheet: pin functions, logic levels, and absolute-maximum ratings, confirmed part by part.
• The bill of materials against the schematic and the layout: every line reconciled to a real component, a real footprint, and a real, sourceable part number.
• The centroid, or pick-and-place file, against the footprints: every placement and rotation checked so the assembler seats each part the way the designer intended.
• The release package against a completeness standard: Gerbers, drill files, BOM, centroid, fab and assembly drawings, and notes, all present and internally consistent before anything is sent out.

None of this is glamorous, and all of it is where boards go wrong. Done by hand, it is slow and easy to shortcut under deadline. That is exactly the kind of work augmentation was made for.

Example: automating a release package with Worthington

On a recent board program, MCG prepared a mixed-signal design for production with our assembly partner, Worthington. The deliverable that decided whether the build went smoothly was the release package, the set of files that tells the assembler exactly what to build and how.

Rather than hand-assemble and eyeball that package, we automated both its creation and the cross-checking behind it. Every BOM line was reconciled against the schematic and against the placement file. Every part rotation was checked against its footprint. The package was validated for completeness, and it was treated as atomic: it shipped only when every check passed, or it did not ship at all.

That is the quiet value of augmented engineering. The manufacturing partner receives a clean, internally consistent package, and the back-and-forth that normally eats days at the start of a build largely disappears.

Why augmentation makes it affordable

The exhaustive cross-check was always the right thing to do. What changed is the cost. An engineer, augmented, can direct an AI to reconcile hundreds of BOM lines, footprints, and rotations in minutes, then verify the results against the source files, work that was never worth billing by hand on a typical program.

The engineer stays in the loop at every gate. The AI extends the reach; the judgment about what is correct stays human. Augmentation without verification is just confident error, and we do not ship that.