SIP-020 — Governance Constraints and Interface Contracts

Go to Annex C: Requirements

The Governance Model SHALL distinguish Governance constraints from Interface Contracts.

A Governance constraint expresses a Policy, Authority, obligation, prohibition, or condition governing structured information or its processing. An Interface Contract defines the conditions under which architectural elements interact and exchange structured information.

An Interface Contract may reference or implement applicable Governance constraints, but the two constructs serve different purposes, have different authorities, and follow different lifecycles. Keeping them distinct prevents an Interface implementation from becoming the unidentified source of Governance Policy or silently modifying an authoritative constraint.

The Submission satisfies this requirement when the Governance Model:

1. Represents Governance constraints and Interface Contracts as distinct architectural constructs
2. Defines the purpose and responsibilities of each construct
3. Identifies the Authority and provenance associated with a Governance constraint
4. Identifies the participants and exchanges governed by an Interface Contract
5. Supports explicit references from an Interface Contract to applicable Governance constraints
6. Preserves the separate identity and version of each referenced construct
7. Prevents an Interface Contract from silently replacing or modifying an authoritative Governance constraint
8. Identifies conflicts between an Interface Contract and an applicable Governance constraint
9. Supports independent lifecycle management of Governance constraints and Interface Contracts

An Interface Contract may specify how an applicable Governance constraint is satisfied at an Interface. The Interface Contract does not become the authoritative source of that Governance constraint unless the applicable Authority explicitly assigns it that status.

The Reference Architecture must preserve the relationship between the authoritative Governance constraint and each Interface Contract that references or realizes it.