Sankey diagrams, also known as Sankey charts, are a type of flowchart that visually depict the flow of materials, energy, or costs between different entities. They are particularly useful for analyzing processes where the quantity of flow is the most significant characteristic. Their distinctive, horizontal, arrows branch out and converge to illustrate the relative magnitude of flow. In this thorough guide, we will walk you through the step-by-step process of creating effective Sankey diagrams using Sankey chart software or by hand.
**Understanding the Basics**
Before we dive in, let’s get a clear grasp of some fundamental Sankey diagram concepts:
– **Main Flow**: The primary direction of flow, typically depicted as horizontal arrows.
– **Branches**: Vertical lines representing intermediate flows, branching off from the main arrow.
– **Tapering**: The width of the arrows narrows as flow decreases to the next entity.
– **Boundary**: Often, a rectangle indicates the beginning and end of the flow.
**Step 1: Define Your Data and Purpose**
First things first, determine what data you want to represent and what the main purpose of your Sankey chart is. Will it be for material flow, energy consumption, financial data, or some other metric?
**Step 2: Gather and Organize Data**
Once you have your goal clear, you’ll need to gather data and organize it appropriately. Make sure that:
– Your data is quantifiable and you understand the units.
– Any processes, materials, or entities that interact with each other are listed.
– It’s straightforward to identify both input and output flow for each entity.
**Step 3: Choose Sankey Diagram Software or Materials**
Sankey diagrams can be created with various tools, from software like Microsoft Excel to specialized Sankey chart software that provides more customization and precision. If hand-drawing, ensure you have ample paper and the correct scale to represent your data effectively.
**Step 4: Plot Initial Sankey Diagram Shape**
Create your basic Sankey diagram structure. Typically, you’ll start with a rectangle for the input(s) and output(s), followed by a main horizontal arrow (the flow of material, energy, or cost).
**Step 5: Insert Branches**
Map out the branches that represent intermediate steps or parts of the process. Ensure that the widths of these branches are proportional to the amount of flow they represent. For complex diagrams, branch out until all entities are accounted for.
**Step 6: Adjust Arrows for Flow Proportions**
Sankey diagrams use tapering arrows to represent the magnitude of flow. Ensure that the flow from primary entities narrows as it passes through smaller processes or branches. This visually shows the relative efficiency or magnitude of different components in the system.
**Step 7: Label and Add Descriptions**
Clearly label each entity, branch, and the main flow. Adding descriptive text on a secondary axis or a separate page can provide context and details about the flow of material, energy, or costs.
**Step 8: Fine-Tune and Refine**
After your initial Sankey diagram is drawn or made using software, review it closely. Look for ways to make the flow of information clearer (e.g., by adjusting the angle of branches, correcting alignments).
**Additional Tips:**
– **Use consistent scales**: Ensure that the scales are uniform throughout the Sankey diagram.
– **Highlight critical areas**: Identify areas with significant flow rates or large losses and consider highlighting them.
– **Consider viewers**: If others will view your chart, ensure it’s easily understandable and tailored to their level of expertise.
By following these steps, you should have an effective Sankey diagram that clearly visualizes the flow of your chosen data. Sankey charts not only provide a quick glance at the distribution of materials, energy, or costs, but also help in identifying potential areas for improvement within a system or process. Whether using specialized software or hand-drawn, your Sankey diagram will be a valuable asset in understanding complex flows and encouraging informed decision-making.
