Data is one of the most popular monetizable elements of the digital age. Therefore, knowing and controlling the flow of data is a strategic necessity. DFD (Data-flow diagrams) is vital to figure out project performance, savings opportunity, productivity improvement, or ways of restructuring an ongoing project.

You also need a DFD to ensure you’re processing the client’s data as per prevailing data privacy laws. In this article, we'll show you how to create a Data-flow diagram for free with online drawing tools like LucidChart.

Symbols of a Data-Flow Diagram

The symbols or notations of any data-flow diagram will depend on the notation you choose, either Yourdon and Coad or Gane and Sarson. For processes, Gane and Sarson's system uses rectangles with rounded corners. However, Yourdon and Coad convention uses circles to denote processes.

Following are the basic components that you’ll need to include in your DFD:

  1. Arrows: Use these to visualize the path of data movement from external entities to the processes and finally to its storage.
  2. Processes: Add a circle to illustrate the processing of data. A process could be a logical sorting, computation, or business rule that results in meaningful data output. Insert a small label to define the name of the process.
  3. Datastores: DFD uses a rectangle with a vertical line to illustrate datastores. A datastore will hold data for other processes to use later.
  4. External Entity: You’ll use rectangles to represent external entities that represent the source and destination of data flow. External entities could be a person, a machine, a group of individuals, or a company.

Related: The Best Google Docs Add-Ons for Creating Diagrams

Steps to Draw a Data-Flow Diagram

Creating a DFD is super-easy. It doesn’t take much of your time for the drawing. But, its utility is multidimensional. Here is how you can quickly draw a DFD for your side hustle, workplace project:

1. Choose a Template

Most of the online diagramming platforms offer ready-to-customize templates to draw data-flow diagrams. You can save a lot of time by using these templates instead of creating a DFD from scratch. However, if your project is complex and no relevant DFD template is available, you can create your own.

Through this tutorial, we’ll draw a data-flow diagram to develop an online food delivery mobile app, for example.

  1. Sign-up for LucidChart.
  2. Open a Blank Document by clicking on the New button in the left-side panel.

2. Customize the Template

If you’ve chosen a template from the drawing app, you can customize that with a few clicks. Here is how:

  1. To rename the texts on the diagram shapes, double-click on the text to rewrite as per your project.
    An image showing renaming texts in a data-flow diagram
  2. To alter the color of the symbols, select one shape, and then click on the Fill Color icon on the top panel.
    A visual showing how to change color of the shapes
  3. To change the color of the arrows, click on them and then alter the color from the Line Color tool.
    A visualization of modifying line color on LucidChart
  4. You can also add new processes, datastores, external entities, and data flow paths from the left-side panel.
    An image showing how to add a symbol in LucidChart

3. Insert an External Entity

An image showing adding an external entity

You’ll need an external data source to start the journey of data through the food delivery app system. Follow these steps to add an external entity to your DFD:

  1. From the left-side Shapes menu, drag and drop a rectangle shape on the drawing canvas.
  2. Double-click on the rectangle shape and label it as Customer.
  3. You can also add color to the rectangle to distinguish it from other symbols within the DFD.

4. Include a Process

Showing how to add processes in DFD using an image

When a customer initiates an order in the app, you need to process the order data. This processing of data ensures timely delivery of the appropriate food item. Add three processes to your DFD by following these steps:

  1. Select a circular shape from the left-side panel and place it on the drawing board.
  2. Label the process as Food Order.
  3. Repeat the above step twice to create two more processes, namely Generate Report and Order Inventory.

5. Add Datastores

A graphical representation of adding datastores in DFD

Before moving order data from one process to another, you’ll need to send processed data to a datastore. Insert three datastores in the data-flow diagram. You can try these steps:

  1. Drag-and-drop rectangles into the drawing board and then resize them as per the image.
  2. Add three smaller rectangles within the above ones.
  3. Rename the datastores as appearing in the image, namely Inventory, Order, and Manager Inputs.
  4. Label the small rectangles with the text D.

6. Include Other Items

An image showing inclusion of additional external entities

As per the current process of data flow within the food delivery app, you need three more external entities to represent the Kitchen, Manager, and Supplier. Find the steps below:

  1. Copy the Customer box using Ctrl+C.
  2. Press Ctrl+V three times to paste three identical boxes.
  3. Rename and position these external entities as shown in the image.

7. Draw the Data Flow Paths

A visualization of data flow path using arrows

After adding and positioning all of the symbols of the data-flow diagram, it’s time to draw the data flow paths between these symbols. Here are the steps to try:

  1. Select any shape and then click on the tiny red circle or Drag line from shape command.
  2. An arrow will appear. Click on it and drag it to the other shape to draw a connecting path.
  3. Now, complete all the paths as per the reference image.
  4. You may want to alter the line colors to distinguish between different types of data flows.

8. Name the Data Flows

A visual showing labelling of data flow paths using texts tool

Once you have the data flow paths, it’s time to label them. To label any shape or flow path in LucidChart, you’ll use the Text tool from the left-side panel or double-click in a blank space to add texts.

9. Add Colors and Fonts

All the elements within the drawing board are fully customizable. You can change the text font, text color, line style, line width, line endpoint, etc.

You can also find other customizations which aren’t on display by clicking on the binocular icon or the Find and Use Features on the top panel.

10. Share the DFD

The data flow diagram is now ready for printing or sharing. You can follow these steps:

  1. To print, hit the print command Ctrl+P.
  2. Click on the Print button in the top left corner.
    An image showing how to print in LucidChart

To share the diagram with your collaborators, follow these steps instead:

  1. Find the Share button in the top left corner and click on it.
    A visual showing how to share diagrams in LucidChart
  2. Add the collaborator’s email.
  3. Select which type of access you want to grant.
  4. Click on Done to send an invitation for collaborative work.

Related: The Best Free Mac Flowchart Makers for Quick and Easy Diagrams

Take Control of Your Data by Visualizing Its Flow

You can create data-flow diagrams of any complexities by following the steps mentioned above. Whether you use LucidChart or any other tool, the drawing process is identical.

DFDs are equally important for productivity improvement in freelance projects, office work, or personal life. You never know how secure your data is on the web. So, it’s good to follow smart practices.