Jim Bailey enhanced the Planning-Inspectorate/data-model repository by implementing data-model updates to support more precise tracking of S78 appeal due dates. He introduced two optional fields—statementOfCommonGroundDueDate and planningObligationDueDate—to the AppealS78Case model, enabling the system to capture critical planning obligation and statement of common ground deadlines. Using Python and TypeScript, Jim focused on schema definition and data modeling, updating both the model definitions and documentation to ensure clarity and maintainability. This work improved data completeness and reporting accuracy, supporting better case management and compliance. The changes were well-documented, with semantic commits and clear rationale for downstream traceability.