Data Flow Diagrams

(DFDs)
1. Introduction
When system analysts attempt to understand the information requirements of users, they must be able to conceptualize how data moves through the organization, the processes or transformations that the data undergoes, and what the outputs are. Through a structured analysis technique called data flow diagrams (DFDs), the systems analyst can put together a graphical representation of data processes throughout the organization. The data flow approach emphasizes the logic underlying the system. By using combinations of only four symbols, the systems analyst can create a pictorial depiction of processes that will eventually provide solid system documentation.
The data flow approach has four chief advantages over narrative explanations of the way data moves through the system (Kendall, 2002).
·Freedom from committing to the technical implementation of the system too early.
·Further understanding of the interrelatedness of systems and subsystems.
·Communicating current system knowledge to user through data flow diagrams.
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