How to Draw Data Flow Diagram?

Data flow diagram is a well known approach to visualize the data processing in business analysis field. A data flow diagram is strong in illustrating the relationship of processes, data stores and external entities in business information system.

A sample data flow diagram

Creating data flow diagram

1. Select Diagram > New from the application toolbar.
2. In the New Diagram window, select Data Flow Diagram.
3. Click Next.
4. Enter the diagram name and description. The Location field enables you to select a model to store the diagram.
5. Click OK.

Notations

Name Representation Description Process A process takes data as input, execute some steps and produce data as output. External Entity Objects outside the system being modeled and interacted with processes in a system. Data Store Files or storage of data that store(s) data input and output from process. Data Flow The flow of data from process to process. Bidirectional Data Flow The flow of data that flow both from and to process.

A list of supported notations in data flow diagram

Decomposing a process

You can create multiple data flow diagrams for different levels of detail. A new level can be decomposed from a process in diagram. To decompose a process, right click on the process and select Decompose from the popup menu. In the sub-diagram you will see the in/out flows that allow you to connect the data flow from parent to sub-diagram. Click here you if you want to learn more about in/out flows.

Decompose process

The Decompose Process dialog box will be prompted to ask you whether to add related data stores and external entities to the new data flow diagram. If you choose Yes, those connected data stores and external entities will be copied to the new diagram.

Choose whether to add related model elements to diagram

Related Resources

The following resources may help you to learn more about the topic discussed in this page.

• New to Visual Paradigm? We have a lot of UML tutorials written to help you get started with Visual Paradigm
• Visual Paradigm on YouTube
• Visual Paradigm Know-How - Tips and tricks, Q&A, solutions to users' problems
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