Stations and travelers — tracking one unit through the line

A Station is a place on the floor where a step of the build happens — an assembly bench, a test bay, a paint booth. A Traveler is the document that follows one unit from "raw kit" to "shipped".

Defining stations:
• Manufacturing → Stations → New Station. Set name, description, and the per-station fields you want operators to capture (e.g. test result, torque value, batch lot of consumed adhesive).

The traveler:
• When a production order is kitted, one traveler per unit is created automatically.
• At each station, an operator scans (or types) the unit's serial / lot, captures the per-station fields, and signs off. The traveler stamps the user, time, station, and (if regulated mode is on) a hash of the prior step linked to the new step.
• When the last station is signed off, the traveler is "completed". The unit moves into finished-goods inventory.

Phone-camera scanning:
• Stations that need a barcode / QR scan use the device camera (no scanner hardware required). On a phone, point at the part's label; the traveler updates instantly.
• A USB barcode scanner works too — it acts as a keyboard, type the scan into the focused field.

As-built genealogy:
• Every traveler records the lots / serials of every consumed component. If you ship a unit and later need to recall it (e.g. component lot defect), Manufacturing → Travelers → Search by component lot returns every finished unit that consumed that lot.
• Conversely, Search by finished serial returns the full as-built tree — which sub-assemblies, which components, which lot of glue, which station signed each step, who signed.

This is the difference between "we built it" and "we can prove what we built and how" — the latter is what aerospace, medical device, and defense customers require.