> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zookooree.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Unit Families

> Three families, one line, different gauges: not everything the factory builds is an agent.

The factory produces three families of unit. All three move through the same seven stations; each is measured with different gauges.

|                    | **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](/certificates). 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                                        |