# TANRAIL ONE — Phase 3.2.4 Pre-Implementation Review

## Design Verdict: APPROVED FOR IMPLEMENTATION

### Architectural Cross-Check
- **Phase 2 Identity/Authorization:** Procurement seamlessly inherits the Contextual Business Unit architecture.
- **Phase 3.1 Data Foundation:** Procurement correctly utilizes the existing `Supplier` and `Item` concepts without polluting them.
- **Phase 3.2 Inventory Core:** Procurement strictly relies on the single-source-of-truth `InventoryService`. It never manipulates `StockBalance` directly. It communicates exclusively via Domain Events.
- **Phase 3.2.3 Sales Precedent:** The Procurement design directly mirrors the proven patterns from the Sales engine (Global Scopes, pessimistic locking, missing fillable fields for mass-assignment protection).

### Future Business Validation
- **Restaurant:** Can buy meat.
- **Catering:** Can buy bulk drinks.
- **Water:** Can buy bottles.
- **Transport:** Can buy vehicle parts.
**Conclusion:** The Core Procurement Engine requires exactly ZERO modifications to support any of these businesses.

There are no architectural contradictions. Implementation may safely proceed.