This article is part of our back-to-basics blog series called what is…?, where we’ll break down some common topics and questions posed to us. We’ve covered much of the content in previous posts, so this series allows us to bring together many disparate resources, creating a single source for your learning. We believe it’s important to take an occasional pulse on foundational knowledge, regardless of where you are in your learning journey. The success of many visualizations is dependent on a solid understanding of basic concepts. So whether you’re learning this for the first time, reading to reinforce core principles, or looking for resources to share with others—like our comprehensive chart guide—please join us as we revisit and embrace the basics.

What is a flowchart?

A flowchart is a type of diagram that depicts a process or workflow. They are often used to communicate complex procedures in a clear, easy-to-understand visual. Flowcharts define specific steps by using text and often shapes, like rectangles and diamonds. Lines or arrows connect these steps to illustrate the proper sequence (or “flow”) of events.

For example, the flowchart below illustrates two possible approaches to organizing a presentation.

Shapes in flowcharts are used to differentiate and describe the specific type of step involved. The more common symbols include:

An elongated oval represents the start and end points of a process.

A decision or question that results in various branches in the process is shown with a diamond .

A rectangle depicts a process, action, or function.

Data input and output are symbolized with a parallelogram.

A rectangle with its bottom side in a wave illustrates a document in a flowchart.

When should I use a flowchart?

A flowchart can be used to analyze, design, document, or manage a process or program in a variety of industries and situations. There are many types of flowcharts, some of which are more common than others.

Data flow diagrams show how information moves through a process or system, including inputs, outputs, data stores, and the various sub-processes.

A data flow diagram for the CDC’s National Program of Cancer Registries.

Program flowcharts show the controls and logic in a system program or algorithm.

An example program flowchart from the SWD July 2020 Challenge.

Swimlane diagrams delineate who does what in a cross-functional process by placing steps within horizontal or vertical “swimlanes” of a particular role, group or department.

A swimlane diagram for a hardware retailer shipment process.

How do I create a flowchart?

Flowcharts don’t follow as many rigid rules as other visualization types—there are no fixed scales or axes, no required proportions, and often no numeric data at all to plot. With so much creative leeway, you can create flowcharts with almost anything, from quick hand-sketched visualizations to help document or plan a process to more comprehensive diagrams created with specialized software.

Falling in the broad spectrum between sketches and custom flowchart software are a number of common business productivity applications. Just about any drawing program or presentation software can create bespoke flow diagrams using text, shapes, and connectors. Links for some common business tools are provided below:

How do I design an effective flowchart?

The same lessons that we cover in our workshops and our books for eliminating clutter and using sparing contrast to direct attention in text and graphs apply to flowcharts (and other diagrams) as well.

Remove or de-emphasize distracting elements in flowcharts

In our visuals, distracting borders or shapes and unnecessary or suboptimal uses of color can distract and confuse our audience. These are elements to remove entirely or push to the background by employing a lighter shade or smaller size. In flowcharts, borders and connecting shapes like lines and arrows can often be pushed to the background.

The flowchart on the left has heavy borders, connecting arrows, and a lot of colors. Compare this with the more simplified version of the same diagram on the right. Borders and some background shading were removed completely, while the arrows and remaining background shading were changed to gray.

Eliminating or de-emphasizing the unimportant elements of diagrams makes it easier to create contrast to direct attention in what remains.

Use color or contrast sparingly to focus attention

Sparing use of color or contrast is an effective way to draw attention to a specific node or section where you’d like people to look. In the same way we can build our graphs piece by piece, it can sometimes make sense to reveal a diagram bit by bit. This is particularly effective in a live setting, where you can control the order and amount of detail your audience experiences at a given time by using animation.

Below is an illustration of highlighting a single node in a flowchart. When presenting live, you might use this to introduce the registration process and then go into detail about that topic before moving on to discussing the rest of the nodes. This approach ensures your audience knows exactly where to look in the diagram at any given time and ensures people don’t jump ahead.

When using a diagram, the goal is to make a concept easier to understand, not more complicated. Employing thoughtful steps to declutter and focus attention can help you achieve this.

To learn more design tips for communicating with diagrams, charts, images, and other visuals, read the Create section of our latest book—storytelling with you: plan, create, and deliver a stellar presentation. You can also find inspiration from our past community challenge: diagram it!