Data Flow Diagrams

What are Data Flow Diagrams (DFD)? #

This is a diagram that maps out the flow of information for any system. There are defined symbols like rectangles, circles, arrows, and so on to distinguish different parts of the system.

There are different kinds of data flow diagrams as well, most are separated into either logical DFD or Physical DFD. Logical data flow diagrams focuses on the system process(es). Physical data flow diagrams show how the data flow is implemented in the system.

Notations #

This section to be written soon.

Rectangle (Entity) #

Circle (Process) #

Rounded rectangle (Data Store) #

Arrow (Data flow) #

Why are Diagrams useful? #

A diagram serves as a roadmap for a project. It shows all the pieces and how they are connected.

How do you draw a diagram? #

First you have to identify the system components and boundaries.

Next you have to pick the paths between these components.

Software for drawing diagrams #

You can draw a diagram with pen and paper. This may be a good way to start because there is a low learning curve involved to expressing oneself in that medium.

When you’re ready for creating a more polished diagram, there are many software availabe.

References #