User talk:Jim4004

This diagramming tool as originated by Yourden and Demarco is not intended as a system-only data flow, but rather to describe a process and how it uses data. There may be both physical and system aspects of a data flow. The power of the tool is that the entire business process can be described in a physical or logical perspective. There may be other tools that attempt to use this to describe objects in a development environment, but those were never the purpose of data flows. The power in a DFD is the ability to debug processes that involve data (digital or physical data)

I think the statement by Ed Yourden was misunderstood "The dataflow diagram is a modeling tool that allows us to picture a system as a network of functional processes, connected to one another by “pipelines” and “holding tanks” of data." Structured Analysis Chapter 9 The "System" referred to is not necessarily an electronic or digital system, but rather a more general system. A system could be entirely physical without any automation. ----Jim4004