Regulatory Configuration Versioning

Strategy

Regulatory rules change frequently. CreditRiskEngine uses a layered strategy to manage configuration changes without breaking existing calculations.

YAML Config Versioning

Each jurisdiction YAML file includes metadata:

jurisdiction: EU
framework: CRR3 / CRD6
effective_date: "2025-01-01"
document_reference: Regulation (EU) 2024/1623

Change Management Process

1. New Regulation: Create a new YAML file (e.g., crr3_v2.yml) or update the existing one with the new effective_date.

2. Amendments: Add amendment metadata to the YAML:

   amendments:
     - date: "2025-06-15"
       reference: "EBA/GL/2025/XX"
       description: "Updated SME threshold"
   

3. Backward Compatibility: The load_config() function accepts an optional effective_date parameter to load the configuration as of a specific date.

Semantic Versioning for the Library

Version Bump	Trigger
Patch (0.1.x)	Bug fixes, documentation, test improvements
Minor (0.x.0)	New features, new jurisdictions, non-breaking API changes
Major (x.0.0)	Breaking API changes, fundamental formula corrections

Regulatory Config Changelog

Changes to YAML configs are tracked separately from code changes:

Date	Jurisdiction	Change	Reference
2026-03-22	All	Initial release with 17 jurisdictions	BCBS d424
2026-03-24	EU, UK	Fixed LGD supervisory values (0.20→0.10 for secured)	CRE32.22-24
2026-03-24	EU	Fixed PD floor from 5 bps to 3 bps	CRE32.13
2026-03-24	EU	Added full LTV-bucket RRE/CRE tables	CRR3 Art. 125-126
2026-03-24	UK	Added loan-splitting configuration	PRA PS9/24