# Protobridge Cost Methodology (open)

How every number on our site — and every real quote we send — is built. Published because black-box quotes are the industry's worst habit.

## 1. BOM (bill of materials)

Per-unit BOM = (compute platform + components + PCB & assembly + amortized enclosure) × 1.12 misc overhead × quantity multiplier.

The 12% overhead covers passives, connectors, cabling, packaging and spares. Reference prices come from open component markets (LCSC and regional marketplaces) at 1,000-unit pricing, then scaled: ×2.6 for 1–5 units (small-lot parts, hand assembly), ×1.35 for ~100 units, ×1.0 at 1,000. Displayed ranges are ±15–25% because exact part selection moves the number. See `open-bom-data.csv` for the full reference table — last verified against LCSC & public listings 2026-07 (`price-check-2026-07.md`).

## 2. NRE (one-time engineering)

Three blocks — electronics design, firmware, enclosure — each in three complexity tiers, plus two conditional adders: antenna design & tuning (any radio) and thermal design (any AI SoC). Rates reflect our East-Asia engineering network — typically 2–4× below global agency averages for the same scope.

## 3. Certifications

Mapped from target markets and device properties: radio triggers FCC 15C / CE RED; lithium battery triggers UN38.3; mains power triggers LVD. Lab fees are indicative ranges; sharing test reports across markets typically cuts total cost 30–50%. Using pre-certified radio modules avoids most intentional-radiator testing.

## 4. What a real quote adds

The instant scan is a rule engine over this data. Before anything is formally quoted, a hardware engineer reviews the spec, corrects component selection, and re-prices against live supplier quotes. Every formal quote is itemized in four lines: parts / labor / outsourcing / our margin. If going direct to a factory is cheaper for your case, we say so.

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*Protobridge, 2026. Indicative data, updated as we run real builds. Not a binding offer.*