Data Flow Diagrams provide a clear understanding of the flow of data through the systems, processes, and users within your organization.

Examples of errors include forgetting to include a data flow or pointing an arrow in the wrong direction. A key reason why keeping data flow diagrams up-to-date is to address issues of system growth.

In our third installment on UML we'll show you how to use sequence diagrams as a tool in your application development and an understanding of object interaction.