How to Make a Data Flow Diagram (DFD) in Visio, Step by Step
A data flow diagram shows where data comes from, where it goes, and where it is stored. Learn the four Gane-Sarson DFD shapes and draw an online order DFD in Visio.
Step by step
Intro
- Data flow diagram. A data flow diagram shows one thing: where data comes from, where it goes, and where it's stored. Let's draw one in Visio for an online order, step by step.
- The Gane-Sarson stencil. I'm using the Gane Sarson stencil. It has only four shapes, and that's all a data flow diagram needs.
Entity and process
- External entity. Start with an external entity. That's a person or system outside our process that sends or receives data. Here, the customer.
- Process. Next, a process. It changes data in some way, so name it with a verb.
- Data flow. Now the most important part, the data flow. It's an arrow, and it must be labelled with the data that moves. Not an action, the data.
Data store
- Data store. Orders need to be saved somewhere. That's a data store, the open-ended box. Put it below the process. Connect the process to the store, and label the data, new order.
More flows
- Add the next process. A confirmed order then moves to shipping. Add a second process.
- Label every flow. Connect them, and label the flow confirmed order.
- Another external entity. Shipping sends a pick list to the warehouse, another external entity.
- Label every flow. Connect it, and label it pick list.
- Done. Click away, and there's your data flow diagram.
The 3 DFD rules
- The 3 DFD rules. Three rules to remember. Every flow is labelled with data. Data never flows straight between two entities or two stores, a process always sits in between. And every process has data going in and data coming out. Subscribe for more Visio tips for business analysts.
