Standards families
IDEF0 function model
Functions as boxes with ICOM arrows: inputs in the left, controls over the top, outputs right, mechanisms below — decomposed level by level.
idef0.basic@1New DDN source
Why use it?
ICOM sides force the question most process diagrams skip: what constrains this, and what performs it?
When it helps
Function analysis in regulated or defence-adjacent programmes, or any "what does the system do" baseline.
How to read it
- The context view is the single A-0 box; the variant decomposes it into numbered child functions.
- Arrows are labelled nouns; the side they enter is the role they play.
What you need
- The top-level function
- Its inputs, controls, outputs, mechanisms
- The decomposition
Things to check
- Do not let an arrow change sides between levels without a tunnel declaration.
- Every parent ICOM must appear (or be deliberately consumed) in the children.
Scope of this diagram
Declared model with ICOM-side validation; conformance certification to the IDEF0 standard is not implied.
Work with the converted example
- Open the viewer and select
context. 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.