How Do You Design Data Flow Diagrams?
The most important objective of any system design is to deliver the stated requirements of the user. Given this, ensuring that your design is adhering to the specifications, you will see three main elements represented by a Data Flow Diagram (DFD)–namely performance, control and changeability. Keep in mind also that your DFD will be eloquent, concise and logically consistent throughout its life cycle. Unlike the flow chart, there is no “Start” or “Stop” in the DFD. DFDs will graphically represent processing of the flow of data as it moves from sources through operations between input and output repositories. You’ll find that in any given system regardless of complexity, you will see three basic operations: input, processing and output. Begin with the input of the system. For example, a publishing company that sells books has two distinct input/output functions, Customers and Publishers. You can use squares labeled “Buyer” and “Publisher” to represent these. Create “Data Stores.” These
