Sankey charts, named after the English engineer William Playfair, are an effective way to visualize the flow of materials, energy, or processes. Their unique ability to depict the quantitative flow of units across a system is invaluable for understanding complex processes and systems. Essentially, a Sankey chart displays energy, material, or cost flows from energy sources, resources, or processes and to products,wastes, or final destinations.
Understanding Data Flow
In this post, we’ll explore the ins and outs of data flow in Sankey charts and how they can be utilized to extract meaningful insights from a vast array of data sources.
At their core, Sankey charts are designed to help you visualize the flow of energy or materials through a system. The width of each pathway is in direct proportion to the quantity of the flow it represents, ensuring that you receive a clear representation of the strength of the data flow at a glance.
Types of Sankey Charts
There are essentially two types of Sankey charts:
1. Horizontal Sankey Charts: This is the most common type of Sankey chart, where the flows are depicted horizontally across the page. It is typically used for depicting the flow of materials, energy, or information, with the process steps running along the top and bottom of the chart.
2. Vertical Sankey Charts: These charts are less common and are used for depicting the vertical flow of information or processes. They are generally preferred when visualizing data that has multiple levels of information or categories.
How to Create a Sankey Chart
Creating a Sankey chart involves several steps, including:
– **Data Collection:** Gathering data points that you want to represent and determining the flow relationships.
– **Defining Nodes:** Nodes are the points at which flows enter and exit the system. They represent different steps in the process.
– **Flow Lines:** Determining the flow paths between the nodes, considering both the direction and the quantity of the flow.
– **Scaling:** Defining the width of each line to represent the flow’s magnitude, ensuring that the relative size of the arrows reflects the quantity of material, energy, or information being transferred.
Interpreting Sankey Charts
Deciphering a Sankey chart involves observing various factors:
– **Width:** The wider the line, the greater the flow.
– **Direction:** Lines running to the right indicate an increase in flow, while those running to the left suggest a decrease.
– **Overlap:** Often, Sankey charts use an overlap effect to show the branching of flows.
– **Color Coding:** If available, color coding can make the chart more visually intuitive, guiding the viewer on which aspects of the process are the most important.
Applying Sankey Charts
Sankey charts have a wide range of applications across various industries, including energy conservation, logistics, financial flow analysis, and environmental impact assessment. Here are some examples of how Sankey charts can be used:
– **Energy Management:** Visualizing energy flows in buildings, industries, or grids.
– **Ecosystems:** Tracking the flow of nutrients or carbon through ecosystems.
– **Business Process Map:** Illustrating the flow of tasks, resources, and roles in an organization.
– **Product Life Cycle:** Evaluating the energy and material flow of a product from extraction of raw materials to manufacturing, use, and disposal.
In conclusion, Sankey charts are an effective tool for visualizing the data flow within a system. They provide a clear and concise representation that simplifies even the most complex processes. By understanding how to read and create these diagrams, you can uncover previously hidden insights and make informed decisions regarding data flow in your field of interest.
