flowdiagram

A flowdiagram is a broad term for any diagram that represents the sequence of steps, actions, or flows within a process, system, or set of data. Flowdiagrams are used to visualize how activities relate, where decisions occur, and how information or materials move from one stage to another. They support analysis, design, documentation, and communication across engineering, software development, business processes, and operations management.

Common elements in flowdiagrams include starting and ending points, process steps or actions, decision points, inputs and outputs, and data stores or queues. Traditional flowcharts use shapes such as ovals for start/end, rectangles for processes, diamonds for decisions, and parallelograms for inputs/outputs, with arrows indicating the direction of flow. Notation can vary by domain, and more formal standards exist for specific uses.

Flowdiagrams cover a range of related forms. Data flow diagrams (DFDs) focus on how data moves between processes and data stores. Workflow diagrams map tasks and approvals in a sequence. Business process modeling notation (BPMN) and UML activity diagrams provide richer, standardized vocabularies for modeling behavior in software and business contexts. In engineering, process flow diagrams (PFDs) illustrate equipment, streams, and process connections in chemical and mechanical systems.

History and development date back to early industrial engineering and the rise of flowcharting as a technique for improving efficiency. Today, flowdiagrams remain a foundational tool for understanding processes, validating requirements, communicating designs, and spotting opportunities for optimization.