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Data Flow Diagram

A data flow diagram (DFD) shows how data moves between processes, data stores, and external entities — a readable architecture view for answering "what data goes where" without committing to behavior or sequencing.

Ngenaire gives DFDs their own dedicated canvas editor at /architecture/data-flow-diagram. Unlike the PlantUML-based UML and SysML diagrams, a DFD is drawn directly on an interactive canvas.

Elements

A DFD is built from four element types:

  • Process — a transformation of data.
  • Data Store — persisted data.
  • External Entity — a source or sink of data outside the system.
  • Data Flow — a labeled arrow connecting elements.

DFDs are typically leveled: a Context (Level 0) view shows the system as a single process with its external entities, then deeper levels decompose each process.

Walkthrough

1. Open the editor

  1. Go to /architecture/data-flow-diagram.
  2. Select a project if you haven't already — diagrams are project-scoped.

2. Create a diagram

  1. Click New Diagram.
  2. Give it a name and (where prompted) a level and description.

To skip the blank canvas, click Generate with AI instead — see AI generation.

3. Add elements

The toolbar has tools for Process, Data Store, External Entity, and Data Flow.

  1. Click a shape tool, then click the canvas to drop the element.
  2. For Data Flow, click the source element, then the target; the flow is drawn as a labeled arrow you can rename.

4. Edit, move, and delete

  1. Click an element to select it; drag to move, and drag a handle to resize.
  2. Double-click an element to edit its label inline, or use Edit Selected for the full dialog (label, description, process number, linked requirements).
  3. Delete Selected removes the selection; flows touching deleted elements are removed too.

5. Keyboard shortcuts

The canvas supports its own shortcuts:

  • Cmd/Ctrl + Z — undo.
  • Cmd/Ctrl + Shift + Z or Cmd/Ctrl + Y — redo.
  • Delete / Backspace — delete the selection.
  • Arrow keys — nudge the selection; hold Shift for a larger step.
  • Cmd/Ctrl + D — duplicate the selection.
  • Cmd/Ctrl + S — save.

6. Save

  1. Click Save Diagram (or press Cmd/Ctrl + S) to persist positions, labels, and metadata.

7. Export

  1. Click the PNG export button to download the current canvas as an image.

AI generation

Click Generate with AI to draft a DFD from your project's existing artifacts.

  1. Optionally set a name, level, and notation, and add free-text guidance for what the diagram should emphasize.
  2. Ngenaire reads the project's requirements, ConOps, SOW, risks, and trade studies and proposes processes, external entities, data stores, and the flows between them.
  3. The draft drops onto a fresh canvas, ready to edit, rearrange, and save like any hand-built diagram.

If the project has no requirements, ConOps, SOW, risks, or trades yet, the generator returns a helpful message rather than an empty diagram.

Tips

  • Keep each diagram readable. Decompose into a deeper level once a diagram has too many processes.
  • Label every flow. Unlabeled flows hide assumptions about what data is moving.

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