Developing Data Flow Diagrams (Cont)
Developing Data Flow Diagrams (Cont)
3. Draw Diagram 0, an “Explosion” of the Context Diagram
- Includes up to Nine Processes, Numbered
- Includes all Major Data Stores and all External Entities
- Ask “What Happens?”, “Where Does This Come From?”, “What Processes Use This Data?”, etc.
4. Create a Child Process for Each Process in Diagram 0
- Obeys “Vertical Balancing” - Cannot Produce Output or Receive Input Unless Parent Does