Processes, interactions and lifecycle
Yourdon-style DFD
A data-flow diagram in the Yourdon idiom: circles for processes, open boxes for stores, named arrows for flows.
dfd.yourdon@1New DDN source
Why use it?
The idiom keeps flows honest: every arrow carries data, every process transforms some.
When it helps
Classic systems analysis and documentation.
How to read it
- Processes are verbs, stores are nouns at rest, entities are outside the system.
- Balancing: a decomposed process shows the same boundary flows as its parent.
What you need
- The processes
- The stores and entities
- The flows with names
Things to check
- Do not draw control signals as data flows.
- Do not decompose a process and lose a flow at the boundary.
Scope of this diagram
The Yourdon idiom as notation; balancing is a modeling discipline, not a validator here.
Work with the converted example
- Open the viewer and select
dfd_yourdon. 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.