SKILL.md
Hardware PRD Skill
A software PRD can ship wrong and patch later; a hardware PRD is cut into steel and soldered onto boards. This skill writes a PRD that forces the decisions that get expensive after tooling: cost targets with a full stack (not just BOM), certifications named per market, reliability as numbers, and forecast assumptions stated so the supply chain can be sized honestly.
What This Skill Produces
- A complete hardware PRD with numbered, testable requirements (shall-statements)
- A target cost stack: BOM → COGS → landed cost, with margin math
- A regulatory/certification matrix per target market
- Reliability, serviceability, and packaging requirements with acceptance numbers
- Forecast assumptions and the EVT/DVT/PVT milestones the schedule hangs on
Required Inputs
Ask for these if not provided; if the brief is thin, infer sensible values and label each one [assumed — confirm]:
- Product concept and user — what it is, who buys it, key use environment (indoor/outdoor, temp range, drop risk)
- Target retail price and channel — retail vs D2C changes the margin stack
- Target markets — determines the cert list (US, EU, UK, etc.)
- Power source — battery (chemistry, size) vs mains changes safety certs entirely
- Forecast — units for year 1 and lifetime, plus confidence
- Launch window and any hard date (e.g. holiday season)
Cost & Certification Framework
Cost stack — always build all four layers; never let "cost target" mean BOM alone:
| Layer | Contains |
|---|---|
| BOM | Components, PCBA, mechanicals, packaging materials |
| COGS | BOM + assembly/test labour + scrap/yield loss + factory overhead |
| Landed | COGS + freight + duty/tariff (HTS code, country of origin) + insurance |
| Margin check | Landed vs channel price after retailer margin (typ. 30–50% retail) |
