EPU Product Graph Ontology

1. Purpose

The EPU Product Graph is the governed relationship network through which ZAYAZ explains a product.

The EPU itself remains a stable identity anchor. The graph connects that identity to product definitions, components, materials, substances, suppliers, organizations, facilities, processes, logistics, production instances, lifecycle events, evidence, calculations, assurance and disclosures.

EPU identifies the product. The EPU Product Graph explains the product.

This ontology defines the semantic contract for graph nodes and relationships. It does not mandate a specific graph database.

2. Graph design principles

Nodes represent governed identities, states, artifacts, events or reference objects.
Edges represent explicit typed relationships; important business meaning must not be hidden in application joins.
Authoritative edges are effective-dated and provenance-bearing.
Graph topology itself may be confidential and subject to access policy.
Historical graph state must be reconstructable.
Source assertions and governed facts must remain distinguishable.
Derived relationships must identify the derivation method and inputs.
Every material product-domain artifact must trace directly or transitively to an EPU.
A graph traversal used for a calculation or disclosure must be reproducible against a defined effective/system-time view.
The ontology is extensible through governed registries, not arbitrary free-text predicates.

3. Top-level node families

IDENTITY
PRODUCT_STATE
COMPOSITION
ORGANIZATION_AND_LOCATION
PROCESS_AND_ACTIVITY
INSTANCE_AND_EVENT
LOGISTICS_AND_CUSTODY
EVIDENCE_AND_CLAIM
SUSTAINABILITY_RESULT
ASSURANCE
DISCLOSURE
REFERENCE_AND_CLASSIFICATION

These are ontology families, not ZAYAZ Modules.

4. Identity nodes

4.1 `EPU`

Canonical product-definition identity anchor.

4.2 `ECO`

Governed organization/legal-entity identity.

4.3 `EBU`

Governed internal business-unit identity.

4.4 `EBP`

Governed project/programme/initiative identity.

4.5 `ExternalProductIdentity`

Representation of an external identifier/namespace such as GTIN, SKU, ERP material ID or PLM ID. This is normally mediated through the Alias Registry rather than treated as an EPU.

5. Product-state nodes

5.1 `ProductDefinitionVersion`

Effective-dated version of the mutable product definition.

5.2 `ProductSpecification`

Technical specification artifact or normalized specification set.

5.3 `ProductFamily`

Grouping/classification node. Product Family is not an EPU by default.

5.4 `ProductVariantClassification`

Optional grouping for variant semantics where useful for catalog navigation or product policy.

6. Composition nodes

6.1 `CompositionVersion`

Versioned BOM/formulation/composition root.

6.2 `ComponentNode`

A component position in a composition structure. It may resolve to another EPU when the component has a governed product identity.

6.3 `MaterialNode`

Material identity/reference used in composition.

6.4 `SubstanceNode`

Chemical/substance reference used for regulatory, hazard and composition intelligence.

6.5 `PackagingNode`

Packaging object kept distinguishable from the primary product/component structure where appropriate.

6.6 `CompositionQuantity`

Governed quantity/mass/share context for an edge or component node. Quantity semantics must retain unit, basis, uncertainty and source.

7. Organization and location nodes

7.1 `Facility`

Physical site/location context. Facility is not automatically a governed ACF identity class and must not be conflated with ECO/EBU.

7.2 `GeographicLocation`

Normalized location/geospatial reference.

7.3 `Port`, `Warehouse`, `DistributionCenter`

Specialized logistics-location nodes where operational intelligence requires them. They may be modeled through a shared facility/location ontology rather than standalone persistence classes.

8. Process and activity nodes

8.1 `ManufacturingProcess`

Governed process definition or process observation used in production context.

8.2 `ActivityData`

Measured, reported, estimated or modeled activity input used by calculations.

8.3 `EnergyInput`

Energy-consumption/generation context where explicit graph representation is useful.

8.4 `WasteFlow`, `WaterFlow`, `MaterialFlow`

Flow nodes where lifecycle or footprint calculations require explicit quantities and provenance.

9. Instance and event nodes

9.1 `ProductionRun`

Production execution context.

9.2 `BatchLot`

Batch/lot identity linked to an EPU and production run/context.

9.3 `SerializedItem`

Lightweight physical-product instance.

9.4 `LifecycleEvent`

Generic governed event envelope for events such as manufacture, sale, transfer, repair, refurbishment, reuse and end-of-life.

9.5 `RepairEvent`

Specialized lifecycle event carrying replaced components, evidence and service context.

9.6 `EndOfLifeEvent`

Specialized lifecycle event for collection, dismantling, recycling, recovery or disposal.

10. Logistics and chain-of-custody nodes

10.1 `Shipment`

Movement of material/component/product quantities between locations or actors.

10.2 `TransportLeg`

A shipment segment with origin, destination, transport mode, carrier, distance/time and activity/evidence context.

10.3 `TransportMode`

Governed reference such as road, rail, ocean, inland waterway, air or multimodal profile.

10.4 `CustodyEvent`

Transfer or assertion of physical/administrative custody.

10.5 `TransformationEvent`

Records conversion of input material/components/batches into output product/intermediate/co-product instances.

10.6 `MassBalanceAccount`

Optional governed object for schemes using mass-balance chain-of-custody accounting. It must remain distinguishable from physical segregation claims.

11. Evidence and claim nodes

11.1 `EvidenceArtifact`

Document, dataset, certificate, measurement, declaration, transaction record or other evidence artifact.

11.2 `Claim`

Explicit assertion such as recycled content, origin, renewable-energy share, substance absence/presence, repairability or product footprint claim.

11.3 `SupplierContribution`

Contribution package from a supplier ECO within a governed scope.

11.4 `SourceObservation`

Raw or normalized observation from a connected source system.

12. Sustainability-result nodes

12.1 `CalculationRun`

Governed computation execution with MICE/method/data lineage.

12.2 `FootprintResult`

PCF, PEF/LCA or other environmental result artifact.

12.3 `ImpactCategoryResult`

Specific impact category result where separate traversal is valuable.

12.4 `ScenarioResult`

Modeled alternative used for optimization or decision support.

12.5 `AllocationDecision`

Governed allocation artifact describing how shared processes/shipments/inputs were assigned to products/co-products.

13. Assurance nodes

13.1 `TrustAssessment`

TrustGate or equivalent governed trust evaluation.

13.2 `VerificationEngagement`

Verifier/auditor engagement context.

13.3 `VerificationFinding`

Finding, exception or approval linked to the exact claim/evidence/result under review.

14. Disclosure nodes

14.1 `DisclosureProfile`

Rules selecting what may/must be disclosed for an audience, framework or jurisdiction.

14.2 `DisclosureArtifact`

Published or draft projection such as DPP, PCF API payload, recycler view or customer sustainability record.

14.3 `ResolverEndpoint`

Governed external resolution endpoint associated with QR/NFC/GS1 Digital Link or other data carrier strategy.

15. Reference and classification nodes

Representative nodes include:

product classifications;
CN/HS/customs codes;
regulatory product categories;
material classifications;
substance identifiers;
hazard classifications;
lifecycle method profiles;
emission-factor/dataset references;
units and functional-unit definitions.

Reference nodes should normally resolve to authoritative ZAYAZ registries rather than duplicate reference datasets inside EPU.