Domain Model

This document defines the core domain models and entity relationships for BayanCore's key workflows: contracting (BOQ), trading, invoicing, and ZATCA compliance.

Core Entity Relationships

Key Business Rules

Contracting Domain

• BOQ approval required before progress billing
• Retention held at 5-10% per contract terms
• WIP tracked against BOQ line items
• Progress billing capped at BOQ total - retention

Trading Domain

• Landed cost = purchase cost + freight + insurance + customs
• Multi-warehouse inventory with batch tracking
• Reorder point triggers automated PO drafts
• FIFO cost flow for inventory valuation

Invoicing & ZATCA

• Every B2B invoice requires ZATCA pre-clearance
• QR code contains TLV-encoded invoice data
• Hash chain links successive invoices for tamper evidence
• PDF/A-3 with embedded XML for archive

Related Documents

• Workflows — Contracting
• Workflows — Trading
• Data Architecture
• Compliance — ZATCA