Streamlining Data: The Art of Illuminating Sankeys

Introduction

In an increasingly digital world, the ability to make sense of complex data relationships is crucial. Among the visual tools available to analysts, the Sankey diagram has emerged to depict complex flows in a clear, concise, and aesthetic manner. This article takes a deep dive into the art and science behind the creation of Sankey diagrams, uncovering their applications and significance in various fields.

The Essence of a Sankey Diagram

A Sankey diagram, named after British engineer and physicist Max Schulze von Bülow, is a special type of flow diagram. These graphs use horizontal arrows to represent the quantity of material, energy, or cost that flows from one process or system to another. In essence, they show how different elements of a system or data source are interconnected and interconverted.

Sankeys are remarkable for their ability to portray the magnitude of flows alongside the complexity of their relationships. They are often used to visualize energy transfer in industrial processes, water distribution, traffic patterns, supply chains, and financial transactions, to name but a few applications.

Key Features of a Sankey Diagram:

Arrows in a Sankey diagram are known as ‘tubes’. The width of each tube represents the amount of flow. This aspect immediately communicates the relative magnitude of the flow between different processes or components.
These diagrams have a single source and a single sink. Flows move from one process to another, and finally, to the sink.
Tubes may merge or split to show how flows combine or diverge at different points in the system.

Crafting the Perfect Sankey Diagram

Creating an effective Sankey takes careful planning and attention to detail. Here’s a step-by-step guide to making a Sankey diagram:

1. Identify Your Data

Start by gathering and formatting your data. It should represent all the quantities you want to visually communicate, whether it’s energy, water, or money.

2. Choose Your Software

There are several tools available to create Sankey diagrams, including:

Sankey Plotter – An online tool that allows for interactive Sankey diagrams.
Excel – With the aid of Power Query and a simple VBA script.
Python – Using libraries such as matplotlib.sankey or plotly.
R – With packages like sankey or SankeyView.

3. Set Up the System

Once you have your data and your software, it’s important to establish the flow of materials or information. Define the processes that make up your system, starting from the source to the sink.

4. Design the Flow Tubes

With your system and the flow established, it’s time to draw the flowing ‘pipes’. Make sure to use a consistent scale to represent quantities. Remember that the width of each pipe should reflect the amount of flow it is conveying.

5. Test and Iterate

The first attempt at a diagram might not be perfect. Check for accuracy, readability, and consistency. Make adjustments as needed and ensure all flows are accounted for.

6. Final Touches

Format the nodes (points of intersection), the labels, and any other additional data you wish to include in your Sankey diagram. Use color coding to enhance readability and meaning, and make sure the overall design follows best practices in data visualization.

Applications of Sankey Diagrams

Sankey diagrams are a versatile tool for illustrating flows that can be found across numerous fields:

Engineering: To identify inefficiencies in energy conversion and distribution within manufacturing processes.
Environmental Science: To display the movement of substances and energies through ecosystems or the flow of greenhouse gases around the planet.
Business Analytics: To visualize financial flows, customer pathways, or the distribution of resources across a company.
Public Policy: To study the flow of information, money, or people, thus aiding in the decision-making process for public projects and investments.

Conclusion

Streamlining data to understand and visualize complex processes and systems is an essential task for any researcher, developer, or policymaker. Sankey diagrams present an elegant and effective means to illuminate the intricate networks that underpin our world. By combining artful design with precise data representation, Sankeys truly illuminate the path forward in interpreting dynamic and often interdependent systems. As we continue to create, analyze, and build upon these visuals, the Sankey diagram stands as a testament to the power of clear and thoughtfully crafted data visualization.

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.