Quick Answer
A client seeking cost-reduction opportunities in a gas control valve assembly had already analyzed the plastic components but had no visibility into the printed circuit board and its electronic parts, because no bill of materials existed for that section. The solution was a physical teardown and reverse engineering of the PCB. Every component was identified directly from the board, position, quantity, value, and specification were documented, the data was validated against supplier databases, and regional pricing was benchmarked to build a complete component-level cost model, all without a single page of documentation from the client.
Context
A client had completed cost analysis on the plastic components of a gas control valve assembly. What remained was the PCB and its electronics, the least visible part of the assembly, despite being one of the more cost-sensitive sections.
Challenge
No BOM existed for the PCB, and no component list could be sourced from documentation
Every electronic component had to be identified directly from the physical product, with no reference drawing to confirm part numbers or values
Component types, specifications, and quantities all needed independent validation before any cost figure could be trusted
Region-specific component pricing was required to support real sourcing decisions rather than generic catalogue estimates
Approach
Physical identification: Each component identified through visual analysis. Package type, markings, and placement on the board.
Structured documentation: Position, quantity, value, and specification recorded for every component, building a complete record rather than a partial list
Supplier database validation: Identified part numbers and values cross-checked against major electronic component supplier catalogs
Specialist collaboration: Electronics costing specialists brought in to establish credible per-component costs
Bottom-up cost model: Individual component costs assembled into a complete cost model for the PCB assembly as a whole
Results
A complete component-level BOM for the PCB assembly, built entirely without documentation from the client
Full visibility into PCB cost drivers that had previously been a blind spot in the assembly cost structure
Cost-saving opportunities identified, supporting sourcing and procurement decisions with component-level data instead of estimates
A more complete should-cost assessment of the overall gas control valve, since electronics could now be analyzed alongside the plastics work already completed
What This Reveals
A PCB is often a small piece of an assembly by part count. It carries a disproportionate share of the cost relative to its size. It is exactly the kind of component that gets skipped in cost-reduction programs simply because nobody has visibility into it. Once a component-level BOM exists, the same teardown methodology and pricing data become reusable for future product revisions, alternate sourcing, or design-for-cost reviews.
Frequently Asked Questions
What does PCB reverse engineering involve when no BOM exists?
A physical teardown of the board to visually identify every component by its markings, package, and placement. Position, quantity, value, and specification are documented for each one, and the data is validated against supplier part databases before a structured BOM and cost model are built.
Why is electronics cost analysis often harder than mechanical cost analysis?
Mechanical parts typically have drawings and traceable material specifications. Electronics assemblies, especially legacy or contract-manufactured ones, often have no surviving documentation, so the analysis has to start with physical inspection instead of a design file.
How is PCB assembly cost calculated once a component-level BOM exists?
Each component is priced using benchmarked, region-specific supplier data, and those individual costs are aggregated into a total assembly cost. It is a bottom-up approach rather than an estimated or quoted lump sum.
Related Reading
This PCB cost-modelling work complements the broader should-cost and VAVE capability at Goken. See the machining and sheet metal should-cost case study for how the same bottom-up, component-level approach applies to mechanical assemblies.
Explore more cost engineering case studies on the Goken Insights library.
If your product has a cost-sensitive component with no supporting documentation, talk to the Goken cost engineering team.
Sources cited: GEP, Should-Cost Modeling and Analysis; aPriori, A Guide to Should Cost Analysis and Negotiation.