Data Flow Diagram

Data Flow Diagrams Visualize How Data Flows Across Systems and Business Processes

A data flow diagram (DFD) visualizes the flow of data through company systems or business processes. They provide simplified views of how companies produce and consume data in their organizations. The data flow diagram is a primary tool for understanding data lineage. This provides intelligence on how data touches various applications, users, and systems to help assess privacy risk and can provide insight into the company’s data protection impact assessment (DPIA).

DFDs have two forms — logical and physical. Logical diagrams show how information moves through a system, the source, the destination, how it is processed, and where the information goes.

Physical diagrams reveal the actual components that data touches for a process, including the software, hardware, and people that are part of the data flow.

What is the Structure of a DFD?

A DFD has a typical pattern, which includes:

  1. Activity – what is the company trying to achieve
  2. Inputs – what data will be used and where it comes from
  3. Outputs – what data will be produced, where will it be stored and how will it be accessed

How are DFDs Used?

While the definition clearly defines what information a DFD visualizes (the flow of data through systems and business processes), there are several contexts for their use:

  • Documenting the overall enterprise architecture of a company.
  • Business process analysis, for designing, or reengineering business processes.
  • Privacy, DPIAs; for understanding the flows and uses of personal information in a company.