Sankey charts are a popular type of flow diagram that effectively visualizes and communicates the movement of quantities between different categories or states. They are named after their inventor, the Scottish statistician and engineer, John V. A. W. D. Sankey, who used this type of diagram in the late 19th century to illustrate the energy efficiency of steam engines. Today, Sankey charts find application in a wide range of fields, from economics and energy management to environmental studies and data analytics.
Elements of a Sankey Diagram
Nodes: The starting and ending points or categories in a flow are represented by nodes. These nodes typically carry labels that describe their content.
Arrows (Flows): These are the main visual elements. Each arrow connects two nodes and is scaled according to the quantity it represents. The width of the arrow is directly proportional to the value it carries, providing a clear visual representation of the magnitude of data flowing through a system.
Labels: These provide context and clarity about the specific flows or quantities being represented.
Creating a Sankey Diagram
Data: The creation process begins with collecting the right data. This information should delineate the sources, destinations, and the flow quantities between them.
Structure Design: Based on the nature of the flow, a logical structure is designed. Each flow must be uniquely identified to ensure clarity and readability.
Visualization Tools: Utilizing appropriate visualization tools is crucial. Software such as Microsoft Excel, R (using packages like ggplot2 or sankeychart), and Python with libraries like Plotly or Matplotlib, can be used to create professional Sankey diagrams.
Sizing and Layout: Adjust the sizing of flows based on their magnitude. This might involve adjusting the widths, lengths, and angles of the arrows to maintain a clean, uncluttered diagram.
Color and Typography: Different colors can be used to distinguish between different types of flows or categories, while maintaining readable typography for labels.
Applications of Sankey Charts
Resource Management: By visualizing the sources and destinations of a particular resource (e.g., water supply, electricity usage), decision-makers can identify waste, inefficiencies, and areas for improvement.
Supply Chain Analysis: In manufacturing or wholesale industries, Sankey charts help track materials and products through factories, warehouses, and the market, identifying bottlenecks and optimizing logistics.
Process Engineering: In chemical processes or any industrial system, Sankey diagrams can clarify material flows, pinpointing where energy or substances are lost or wasted.
Data Analytics: Web analytics, for instance, can use Sankey diagrams to illustrate user journeys, showing the paths users take through a website and where they drop off.
Benefits of Using Sankey Charts
Enhanced Understanding: Quick comprehension of complex data flows, making it easier for stakeholders to grasp the overall system dynamics.
Decision Support: Revealing insights that can guide resource allocation, process improvements, or strategic planning by highlighting the most significant flows.
Engagement and Communication: Visually appealing and engaging, Sankey charts are effective in communicating findings and trends to a diverse audience, including non-technical stakeholders.
Conclusion
Sankey charts are a powerful tool for data visualization, allowing us to see the flow of materials, resources, or information in a comprehensive and understandable way. Whether tracking supply chains, analyzing energy consumption, or visualizing user interactions, the ability to effectively communicate flow data through Sankey diagrams is invaluable. Designing and implementing these charts requires careful planning and the use of appropriate tools, but the insights gained make the effort well worth it. So, consider leveraging the power of Sankey diagrams in your data analysis projects to unlock new levels of understanding and efficiency in your work.
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.
