Overview of Data Flow Diagram
Data Flow Symbols Unique Names for Data Flows. No two data flows should ever have the same name. (Remember, data is transformed by a process, so the input and output data flows from a process will have different names.) Data Flows should be consistent and cascade among levels. For example, if a “Student” EE provides an application to a process on a level 1 DFD (Figure 1 or Figure 2 or Figure 3), then it must appear on the Figure 0 DFD and the context diagram As a quick double-check before you turn in home work and projects: Count all the data flows on your context diagram from each EE. On the level 0 diagram, the counts should be the same. Cascade this rule for each subordinate level. NOTE: You should perform this same check for each data store. Process Symbols DFD Process symbols have 3-parts : a numeric id on top, a verb-object process label in the middle, and an actor-place...