Data Flow Keynote Diagrams is another means of modeling the functional requirements for the future system. Keynote diagrams are presented in the form of a hierarchy of processes associated with data flows. Data flow diagrams show how each process converts its input data into output, and reveals the relationship between these processes.
Flow Keynote Diagrams are successfully used as a supplement to describe the document flow and information processing. The appearance of the components may vary, but the set remains unchanged.