# Process Logging and Traceability

Every step of production is logged continuously, so that every record is
traceable end to end for the customer. This is a set requirement, and it is
the core specification for the factory software this repository will
eventually host.

It is also the part of the plan the industry responds to. At Making Vinyl
Europe 2026 most people the team talked to were strongly interested in it,
and Sibert's representative named it as a reason to work with a newcomer
he would otherwise have advised against building a plant; buildfor.life's
development and data work settled the question for him (see the
[exhibitor briefing](suppliers/making-vinyl-europe-2026-exhibitors.md#after-the-show)).

## What a customer can trace

For any order, the customer can follow the full chain:

1. **Audio intake**: file received, checksums, versions, who handled it,
   approval trail
2. **Mastering**: session log, engineer, settings, customer approvals
3. **Cutting**: lacquer IDs, lathe parameters, stylus used, inspection
   result
4. **Galvanics**: silvering and plating batch IDs, bath chemistry logs,
   father/mother/stamper genealogy (which stamper came from which mother
   from which father), or the external stamper supplier and batch if bridged
5. **Pressing**: press ID, operator, shift, mold and stamper IDs, cycle
   parameters (temperatures, pressures, cycle times), PVC compound lot and
   virgin/recycled mix, label lot
6. **Quality control**: test pressing approvals, inspection results, reject
   counts and reasons (the automated instrument layers feeding this are
   specified in [quality automation](quality-automation.md))
7. **Finishing and packaging**: trimming, sleeving, carton lot, packaging
   partner batch
8. **Fulfillment**: warehouse location, shipment or dropshipping consignment,
   carrier tracking per end customer

## Principles

- **Log at the source**: machine data comes from the machine (the presses
  and the plating rectifiers expose PLC data; the AD12 supports remote
  monitoring), not from manual transcription. Manual steps get simple
  operator check-ins, not paperwork.
- **Batch and genealogy first**: every physical artifact (lacquer, father,
  mother, stamper, press run, box) gets an ID, and every ID knows its
  parents. A customer complaint about one record resolves to a specific
  stamper, press, shift, and compound lot.
- **One system of record, one set of keys**: every record of the
  business and of production (orders, gates, work orders and job cards,
  batches, quality inspections, metal parts and their genealogy,
  deliveries, invoices) lives in ERPNext, which the whole plant runs;
  only machine data (per-cycle rows, per-record results, telemetry, audio
  captures) lives outside it, carrying the same ERPNext document names,
  so a trace and an invoice point at the same order
  ([digital factory](digital-factory.md#erpnext-the-plants-erp)).
- **Environment attached**: the whole-factory HVAC monitoring (temperature,
  humidity, PM per zone) is logged on the same timeline, so any production
  window can be correlated with plant conditions.
- **Immutable and retained**: logs are append-only and retained for the
  life of the customer relationship; stamper genealogy is retained as long
  as the archive holds the metal parts.
- **Customer-facing view**: traceability is a product feature, not an
  internal file. Customers get a per-order view (portal or report) covering
  the chain above, without exposing other customers' data. The investor
  demo [make a record](make-a-record.html) shows the per-copy version a
  fan reaches from the code printed on the sleeve, the **record passport**:
  stamper, press, cycle time and side, with the stage dates and the
  inspection result (IDs simulated). The per-order view itself is shown
  in the [factory console and order status](factory-console.html) demo:
  the customer follows the order through the gates, sees how many copies
  are pressed so far and the results of every inspection station, from
  the lab certificate of the compound lot to the listening checks.

## Open design work

- Data model for batch genealogy across all eight steps
- Which PLC/machine interfaces each vendor exposes (ask Newbilt, Pheenix
  Alpha, and Digital Matrix during procurement, before purchase)
- Retention, backup, and PDPA handling for operator-linked records
- Whether test-pressing approval workflows live in the same system from day
  one

This system should be specified alongside equipment procurement: machine
data access is a purchasing requirement, not an afterthought. The systems
that implement this specification (machines, networks, collectors,
database, application) are planned in [digital-factory.md](digital-factory.md).