Sankey
Use a Sankey chart when visualizing the flow between sets of values.
A Sankey chart is great to use when visualizing the flow between sets of values. A more complex Sankey will have multiple levels. To build a Sankey chart in Varicent ELT, we require the following pieces of information:
From - First column of the Sankey chart
To - Final column of the Sankey chart
Value - Numerical
To create a Sankey diagram, you need to have data segmented into categories.
Caution
You cannot create a Sankey diagram with cyclical values. The From and To fields cannot contain the same values if they would flow into each other. Put another way, if a value would flow from one category into the same category, this will cause an error.
When to use this tool
Use a Sankey diagram when you want to show how values map between two categories.
Example
You could use a Sankey chart to show how budget categories flow into different departments. This is a simple example with only a few categories, but you can use Sankey diagrams to show complex value flows. Our example data set looks like this:
Department | Budget (in thousands) | Category |
|---|---|---|
Sales | 80 | Personnel |
Sales | 40 | IT |
Sales | 20 | Misc. |
Development | 120 | Personnel |
Development | 67 | IT |
Development | 30 | Misc. |
Support | 75 | Personnel |
Support | 45 | IT |
Support | 12 | Misc. |
HR | 72 | Personnel |
HR | 20 | IT |
HR | 10 | Misc. |
When we create a Sankey diagram using this data, we can show how each department's budget flows into the different categories. We can easily see which departments are spending the most in each category and how much of our total budget each category represents.
Creating a Sankey diagram with more than 2 columns
Tip
When creating a Sankey diagram with more than 2 columns, it is helpful to do some planning in advance, and consider how to organize your data set.
For example, below is a sample data set. Investigate and think about how A flows to B, and then B to C. Map and write that down before listing the ribbons below A.
From | To | Value |
|---|---|---|
A1 | B1 | 4 |
A1 | B2 | 2 |
A2 | B1 | 1 |
A2 | B2 | 3 |
A3 | B1 | 2 |
A3 | B2 | 1 |
B1 | C1 | 2 |
B1 | C2 | 2 |
B1 | C3 | 3 |
B2 | C1 | 2 |
B2 | C2 | 4 |
This data set illustrates this Sankey diagram:
