The Visual Art of Flow: Decoding Sankey Charts Unraveled

Introduction

The Sankey chart, named after English engineer and inventor William Playfair, is a type of flow diagram used to visualize the quantities or strengths of flows between systems. They are distinct and particularly elegant in their ability to depict the flow of energy, materials, or finance over time, highlighting those with the strongest “flows” as thicker streams within a network or process.

Sankey charts are highly valued in a variety of fields for their power to simplify complex data into a comprehensible form. Their visual clarity makes them excellent tools for understanding the distribution and transformation of resources, energy distribution, network traffic, and many other systems with interconnected components.

Understanding Sankey Charts

Basic Components

A Sankey chart is composed of nodes, which represent entities, and links, which represent flows between these entities. These components are crucial in encoding information:

Nodes: The intersection points of the links wherein resources are introduced, transformed, or extracted from the system.

Links: Arrows that indicate direction and quantity of the flows between nodes. The thickness of the links generally corresponds to the amount of flow.

Key Features

• Sankey charts must maintain the direction of the flow, either from left to right or top to bottom.
• The stream width changes in accordance with the quantity of flow; a thicker link shows a higher flow.
• The direction of flow must remain consistent throughout the chart, often from the input or origin to the output or destination.
• There should not be any overlap between the Sankey chart’s elements.

The Creation Process: A Multifaceted Challenge

Creating a Sankey chart is a process that blends art with the precision of data analysis. Here’s a step-by-step guide to creating one:

1. Gathering Data

Begin with a clear understanding of the system you wish to visualize and collect data on how flow moves through it. Sankey charts excel at showing both the total flow and the breakdown of flow by the types of links.

2. Establishing Nodes and Links

The initial step in the creation process is to map out the nodes and links. Nodes represent components of the process that inputs, transform, or output flows, while links represent the pathways the flow takes. The mapping must accurately represent the process under inspection.

3. Determining Flow Quantities

For each link, it is essential to determine the actual amount of flow, often in units like tons of material, megawatts of energy, or dollars transferring between entities.

4. Drawing Initial Sketch

Using the collected data, draw an initial sketch of the Sankey chart in a manner consistent with the principles described earlier. This stage is more of an artistic interpretation, guiding the precise numerical values in the next step.

5. Assigning the Quantitative Data

Once the sketch is in place, assign the data to each thickness for the links. Sankey chart software often allows for manual adjustment of the links’ thickness, reflecting the actual data inputs.

6. Fine-tuning and Presentation

Adjust the chart for readability, ensuring that it accurately depicts the process or system. Use labeling and annotation to provide clear information about each component of the chart.

Applications of Sankey Charts

Energy Flow

Sankey charts are extensively used in the energy industry to visualize energy flow, making it easier to understand how energy is transformed and lost in different energy conversion steps.

Financial Flow

Understanding the flow of money within an organization or financial system is another area where Sankey charts shine. They are used to demonstrate where money is incoming or outgoing, and how these flows connect various departments or operations.

Material Flow in Manufacturing

The creation of a Sankey chart helps to visualize the transformation of materials within a manufacturing process, showing where materials enter, how much is transformed or discarded, and the resultant outputs.

Network Flow

In network analysis, Sankey charts clarify the routing of data or network traffic, whether on the internet or within complex internal network infrastructures.

Conclusion

Sankey chart creation is an intricate art that requires both a sound knowledge of the system under examination and an understanding of how to visually communicate the data. As a powerful visualization tool, Sankey charts facilitate decoding complex flows and processes by distilling vast numbers into intuitive graphical representations. Whether you are an engineer, a financial analyst, or a network administrator, unlocking the visual art of flow with Sankey charts can provide insight into the hidden complexities of your systems.

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.