Batches & serial numbers

Purpose
For goods requiring proof, what counts is not the quantity but which item went where.
The serious case decides this module's worth: when a supplier reports a faulty batch, the question is not whether any is left but who it went to. Only the usage record answers that — and it cannot be established retrospectively.
Scope
- A proof requirement per item as a switch — not every item needs traceability.
- Batch stock with best-before dates.
- Serial numbers for tracking individual units.
- A usage record: where a batch or serial number went.
- Batch blocking as its own permission — it halts selling and dispatch.
Interplay
Stock comes from the product catalogue; labels carrying batch details are printed by the print module. Across several locations, the distribution of multi-warehouse applies.
Limits
- There is no retrospective traceability. Setting the requirement late leaves the past uncovered.
- A block acts on stock, not on what was dispatched. The usage record is for that.
- No batch management, no best-before date. The date hangs off the batch.
- No quality management. The module traces; it does not assess.