| Skills | Tools | Agents | |
|---|---|---|---|
| Factory role | Parts — stamped, interchangeable | Jigs, fixtures, machines | Vehicles — integrated units |
| Verify emphasis | Skill validator plus planted-bug fixtures; the genchi genbutsu rule: validated on a real target environment, never only in theory | Software tests plus the tool-provisioning contract; tools are used by both factory and products, so a tool failure is a line-stopper | Full eval suite plus trial production: N supervised runs on real work before certification — Toyota never skips pilot builds; neither do we |
| Certificate expiry | On dependency change | On runtime or API change | Shortest interval; also on model swap or any context-stack edit |
| Volume expectation | Highest | Low | Lowest — and that is correct; agents are assemblies |
Why one line beats three processes
A separate process per product type triples the standard work and lets discipline decay in whichever process runs least often. One line with adjustable gauges means every unit — a five-line skill or a full agent — passes the same stations, carries the same work-order shape, and earns the same kind of certificate. The family changes what the gauges measure, never whether the gauges run. The family is declared at intake: the work-order schema requires it, and the intake linter rejects an order that does not name one.The flywheel measure
The factory’s reuse target — more than half of each agent’s bill of materials drawn from the registry rather than fabricated bespoke — becomes measurable here: percent of the BOM from standard parts versus custom fabrication. Rising reuse is the interchangeable-parts flywheel working: every certified skill makes the next agent cheaper to build and easier to trust.Self-audit
| Claim | Source |
|---|---|
| Three families, one line, different gauges — full table | docs/factory-design.md:166–173 |
| Unit family declared at intake; schema-enforced | docs/factory-design.md:101; workorders/validate-work-order.py (WO-102) |
| >50% reuse target; BOM-from-registry as the measure; flywheel | docs/factory-design.md:175 |
| Trial production for agents is non-negotiable | docs/factory-design.md:171, 269 |