Standards families
ORM fact model
Object-Role Modeling: entity types, value types and the fact roles between them, with uniqueness and mandatory constraints drawn on the roles.
orm.basic@1New DDN source
Why use it?
ORM verbalises facts in sentences non-modellers can confirm, and the constraints are drawn where they apply.
When it helps
Deep domain modelling where every constraint must survive a business review.
How to read it
- Ellipses are object types; boxes on the fact lines are roles — read a fact as a sentence across the roles.
- Bars over roles are uniqueness constraints; dots are mandatory — each is a separate, checkable claim.
What you need
- The fact types as sentences
- The object and value types
- The constraints per role
Things to check
- Do not model a ternary fact as two binaries — the constraint semantics differ.
- A role with no uniqueness reading is an unfinished sentence.
Scope of this diagram
Declared fact model with constraint validation; schema generation is a separate step, not claimed here.
Work with the converted example
- Open the viewer and select
model. Inspect the rendered view and its source. - Open the designer. Keep the selected profile and inspect its legal palette and property controls.
- Change one displayed title or an appropriate data value. Apply the edit and check the resulting diagram.
- Run the verifier and review its diagnostics before moving complete content into review.
- Download your edited DDN source to retain the change.
The example uses the indentation-based ddn-next-1 dialect. The language guide explains reusable definitions, dotted data rows and explicit property blocks.