Part Data Ownership

Data belonging to a part must use that part as its source of truth. Inspect and reuse its existing type definitions, schemas, validation, and business operations instead of creating a parallel domain model. If an extension is needed, explain the proposed change and obtain approval before extending the shared definition.

Philosophy

One domain model avoids duplicated rules and keeps part data consistent across interfaces.

Correct

Events: Use the events part’s existing event definitions and operations.
Blog posts: Use the blog part’s existing post definitions and operations.
Products: Use the products part’s existing product definitions and operations.

Incorrect

Events: Introduce an independent event model instead of using the events part.
Blog posts: Introduce an independent post model instead of using the blog part.
Products: Introduce an independent product model instead of using the products part.

Fix

Use the owning part’s existing definitions and operations. Request approval before extending its shared definition.