Data Flow Diagram
A Data Flow Diagram (DFD) is a graphical representation of the flow of data through an information system, modeling its processes, data stores, data flows, and external entities. It is used in systems analysis and design to visualize how data moves between different components, helping to understand, document, and improve system functionality. DFDs are hierarchical, with levels ranging from high-level context diagrams to detailed process decompositions.
Developers should learn and use Data Flow Diagrams during the requirements analysis and system design phases of software development to clarify data interactions, identify bottlenecks, and ensure data integrity. They are particularly useful for complex systems, such as enterprise applications or data-intensive processes, where visualizing data flow aids in communication with stakeholders and debugging. For example, in designing a payment processing system, a DFD can map how transaction data moves from user input to database storage and external APIs.