The Most Common PCB Production Data Mistakes We See At VESLA
A missing part number, an outdated drawing or an unclear test limit can all hold up production preparation. To understand where handovers go wrong, we brought together feedback from Jaromír Sysel, Production Manager; Radka Dvořáková, Purchase Assistant & General Operations; and Vojtech Pardubicky, Technical Director at VESLA. The recurring issues they shared are the starting point for this article, with practical advice on making your next production package easier to work with.
The following examples illustrate the types of problems they reported and how to prevent them.
1. Quantities that do not agree
Radka and Jaromír both highlight incorrect or incomplete quantities. A BOM may specify a component quantity that does not match the corresponding positions in the assembly data, leaving the team to determine which source is correct.
That uncertainty can affect material purchasing and the quotation. Before release, reconcile BOM quantities with the reference designators and assembly variant. Make intentionally unpopulated positions explicit.
2. Part numbers that leave room for interpretation
Missing or unclear manufacturer part numbers are a recurring sourcing problem. Production documentation can also contain incorrect product codes or obsolete material references.
For example, a component description may identify a value and package without identifying the exact orderable part. The team then needs clarification before proceeding.
Use complete manufacturer part numbers and check that internal and supplier references still point to the intended component. Keep the product code, board revision and assembly variant clearly identified throughout the package.
3. Components that are no longer available
A BOM can be technically correct while containing obsolete, discontinued or difficult-to-source parts. Radka identifies this as another common obstacle.
The consequence may be additional sourcing work or a need to assess alternatives before the project can proceed. Review component availability early and record approved alternatives where possible. If no alternatives are approved, make the approval process clear so substitutions can be reviewed properly.
4. Incomplete or outdated build documentation
Jaromír’s feedback includes incomplete manufacturing documentation and outdated documentation for jig production. A revised board paired with an older fixture drawing, for example, can create conflicting instructions for production preparation.
Release the documents together and make their relationship clear. Check assembly drawings, manufacturing instructions and jig documentation against the current product configuration. Identify superseded files so they cannot be mistaken for the approved release.
5. Special requirements that are never written down
A designer may know exactly how a product should be assembled, but the production team can only work from the information it receives. Jaromír flags missing specific requirements as a recurring issue.
Requirements for special processes or assembly steps need to be included in the released documentation. If they emerge after quotation or production preparation, the team may need to revise the workflow, instructions or cost estimate.
Ask a useful handover question: could someone unfamiliar with the design understand every required production step from this package?
6. Test instructions without clear acceptance limits
Incorrectly specified test parameters and incomplete product quality requirements create uncertainty about whether an assembly is acceptable.
An instruction to check an output, for example, remains incomplete if the required test conditions and acceptable range are missing. Define the parameters, limits and pass/fail criteria, and confirm which test procedure and fixture revision apply.
Agree the quality requirements before production so inspection and testing have a clear, shared basis.
7. Orientation that is unclear across the files
Vojtech highlights missing or incorrectly placed pin-1 indicators. If the layout and assembly documentation do not communicate orientation clearly, the team needs to resolve that uncertainty before assembly.
Check polarity and pin-1 markings against the component datasheet, footprint and assembly drawing. Pay particular attention when components or footprints have changed between revisions.
Resolve open questions before the handover
Preparing a release or transferring an existing product? Bring your files and unresolved questions to a VESLA preparation meeting. Sales can coordinate the discussion with Radka, Jaromír, Vojtech and the relevant specialists, so sourcing, build documentation and DFM are considered together. You get input from the people involved in preparing and supporting your production.
