Use Cases of Waterfall charts in Tableau
Waterfall charts are best used to visualise part-to-whole relationships if some of the dimension values are negative. To avoid confusing them with a simple running total calculation try to think about them as illustrations of how each dimension member (positively valued) adds to a running total whereas a negatively valued dimensions members detract from a running total.
Use the following 6 steps to help you create them in Tableau:
1. We’ll use the Little League dataset to visualize how each player position is contributing to total runs. From the Players’ sheet, drag Position to Columns and Runs to Rows. This will create a vertical bar chart showing the measure (total runs), by the dimension (player position):
2. Next, add a table calculation to the Runs measure, to calculate a “Running total”. Choose the “Compute using options> Table (Across)” from the options available. See Cloudstream’s post on Tableau Calculations in Tableau as a reminder. Your view should be similar to the following:
3. From the view above, we’re now able to see how the running total cumulates across various players’ positions, yet we ’re unable to visualise whether there is a positive or negative contribution of specific dimension members. At the Marks card, change your “Automatic” to the “Gantt Bar” mark type to switch from your current bar chart to the new chart option.
4. Additionally, create a calculated field as displayed in the image below. This is a quick trick to make your Gantt bars for each dimension member lined up i.e create a lining up effect between the tops or bottoms of each bar on the Y-axis.
5. Drag your new calculated field to the Size Marks Card creating the following waterfall effect:
6. Add a few additional steps to your work to help polish the final view by further editing or formatting your axis, colouring Gantt bars by Runs by dragging the Runs measure to the Color Marks Card. Subject to your preferred colour choice the two-toned bar will help distinguish your positive and negative values.
You could also choose to add Row Grand Totals to your visualization by navigating to Analysis > Totals in the top navigation and choosing “Show Row Grand Totals” or simply sorting Runs by Player positions
Depending on your business requirements or the to-be-addressed questions, waterfall charts provide you with the necessary flexibility to experiment with dimension members’ sort orders, adding inherent flexibility to your visualisation.