A Waterfall Chart is useful when you want to show how parts successively build up to a whole. In the following screenshot, for example, is a Waterfall Chart showing how profit builds up to a grand total across Departments and Categories of products. Sometimes profit is negative, so at that point the Waterfall Chart takes a dip, while positive values build up toward the total:

Here are the features and techniques used to build the chart:

• The SUM(Profit) field on Rows is a Running Total table calculation (created using a Quick Table Calculation from the drop-down menu) and is computed across the table.
• Row Grand Totals have been added to the view (dragged and dropped from the Analytics pane).
• The mark type is set to Gantt Bar and an ad hoc calculation is used with code: SUM(Profit). This allows the Gantt Bars to be drawn back down (or up for negative profit) toward the end of the previous mark.
• Category has been sorted Ascending by Sum of Profit so that the Waterfall Chart builds slowly (or negatively) at the left of each Department. You might want to experiment with the sort options to discover the impact on the presentation.