Standards families
SysML requirements diagram
Requirements with id and text, wired by satisfy/verify/derive/refine relationships to the model elements that answer them.
sysml.requirements@1New DDN source
Why use it?
A requirement with no satisfy link is a wish; a design element traced to no requirement is a luxury — the diagram shows both.
When it helps
Contract-driven development, compliance arguments, coverage reviews.
How to read it
- Boxes labelled «requirement» carry the id and text; dashed arrows are the trace relationships, read with their keywords.
- A verify link must end at a test case; a satisfy link at a design element.
What you need
- The requirements (id + text)
- The satisfying design elements
- The verifying tests
Things to check
- Do not paraphrase requirement text in the box — quote it, or the trace is to your summary.
- Refine is not satisfy: refine clarifies, satisfy answers.
Scope of this diagram
Declared traceability with relationship-type validation; coverage is shown, not certified.
Work with the converted example
- Open the viewer and select
requirements. 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.