in the middle of the 1970s. It was first proposed by Larry Constantine, and popularized by Edward Yourdon, Tom DeMarco, Chris Gane and Trish Sarson, who enriched the diagramming technique with different notations, data dictionary practices and guidance for the hierarchical decomposition of processes.

The primary aim of data-flow diagrams in the context of structured design was to build complex modular systems, rationalizing the interdependencies across