Data Flow Diagrams (DFD) Explained

We all happen to be in situations when we need to explain something a bit complicated to somebody without challenging the fabric of reality. It takes some time and a whole lot of effort and usually isn’t very helpful.


You try to break things down even more — into digestible bites, you try to elaborate on certain aspects, with extensive use of verbose out-there constructions — but it doesn’t really get anywhere further and adds more confusion instead. 


In IT-segment — that is a relatively typical challenge, and there is a thing to deal with it. Data Flow Diagrams is its name.


What is Data Flow Diagram?

Data Flow Diagram is a type of diagram chart that shows the movement of information from one place to another as part of a particular processor in general. In other cases — DFD can show how different departments of the organization cooperate - it makes things clear and coherent. 


The entire method was devised back in the 1970s as a mean to streamline documenting and subsequent presentation of the workflow processes.


  • Dataflow diagram was first described in a book by Ed Yourdon and Larry Constantine, “Structured Design.” 

  • They took “data flow graph” models of computation of David Martin and Gerald Estrin as the foundation.

  • Other significant sources of inspiration were Object-Oriented Analysis and Design and Structured Systems Analysis and Design Methods.

  • The method was further perfected by Tom DeMarco, Chris Gane, and Trish Sarson, who devised a practical alphabet of symbols and notations for Data Flow Diagrams.

At this point, DFD is more or less replaced by Business Process Model and Notation aka BPMN and is rarely beyond showing the big picture.


However, Dataflow diagrams is a good entry point for those who starts studying Business Analysis and business process visualization.


DFD shows what goes where and how and explains how exactly something operates and what happens in the process.