Flowcharts Elevated: Mastering the Art of Sankey Charts

In the intricate tapestry of data visualization, the Sankey chart stands out as a distinctive tool that beautifully illustrates complex flows of information, energy, or materials. Similar to the more common bar, pie, or line charts, Sankey charts aim to convey patterns and relationships without overwhelming the viewer with details. But there’s a unique elegance and subtlety to the Sankey chart that gives it an edge in conveying the intensity of flows—both the big and the small—across a variety of fields. This article takes a deep dive into understanding Sankey charts, the art of creating them, and their vast applications.

What is a Sankey Chart?

At first glance, a Sankey chart may seem just like a specialized flowchart. Upon closer inspection, its distinctive feature—the narrowing and broadening of paths—comes into focus. Each path in a Sankey chart represents a flow of energy, a material, or information, with the width of the path directly corresponding to the magnitude of the flow.

Sankey diagrams were created in the early 19th century by an engineer named William Playfair. Since then, they have evolved to become a popular method in many disciplines for visualizing the direction, magnitude, and efficiency of flows in a process. Each Sankey diagram is designed by the creator to fit a specific scenario, making it a highly flexible communication tool.

Mastering Sankey Chart Creation

To create a Sankey chart, one must understand the principles that guide its design. Here are some key concepts and tips for creating effective Sankey charts:

1. Define the Flow

Identify the main flows of interest. Whether you’re tracking the flow of water through a treatment plant, energy within a system, or money in a financial model, clearly defining the flows is crucial.

2. Choose the Right Visualization Tool

Select a tool that supports Sankey chart creation. This could be a specialized software like Sankey Diagrammer or a more general data visualization package like Tableau or Power BI.

3. Structure the Flow

Decide how the flows start and end and where they branch out. Typically, Sankey charts begin from a source and end at a destination, with multiple paths to depict the sub-flows and interactions within the system.

4. Maintain Consistency

Maintain consistent scaling across the chart. The width of the arrows should accurately depict the relative magnitude of the flow, so it is essential to standardize the unit of measurement.

5. Simplify and Exclude

Minimize the number of elements to maintain clarity. There’s no need to show every aspect of your data; focusing on the key points and simplifying where necessary can help improve the readability.

6. Test Your Chart

Before finalizing, test your chart to ensure it communicates the intended message clearly. Present your Sankey chart to a non-expert to gauge their understanding.

Applications of Sankey Charts

Sankey charts have a broad range of applications across various industries:

1. Energy Systems:
   Evaluate energy conversion processes, renewable energy systems, and carbon footprints to understand the efficiency of energy use.

2. Environmental Engineering:
   Track the flow of water or waste through municipal water systems and recycling facilities, highlighting areas for improvement.

3. Economics and Finance:
   Map the flow of funds, showing financial inputs and outputs for companies and organizations.

4. Data Science:
   Visualize data transformations in machine learning models and identify bottlenecks in data processing.

5. Complex Systems:
   Analyzing the complexity of information passing through a network, such as communication networks or social media activity.

6. Business Processes:
   Identify stages of decision-making or workflow efficiency by tracking the flow of materials or activities.

Conclusion

Sankey charts are powerful tools for illustrating the movement of energy, material, or information across a system. They have the unique ability to communicate complex information in an intuitive way, making them an invaluable asset to many fields. As you master the art of Sankey charts, remember to focus on clarity, consistency, and simplicity—these are the keys to creating impactful visualizations that will elevate your understanding and communication of flow dynamics.

SankeyMaster

SankeyMaster is your go-to tool for creating complex Sankey charts . Easily enter data and create Sankey charts that accurately reveal intricate data relationships.