Sankey Diagram: requirements gathering

In this blog post, we cover:

Layout - 5 steps to understand how the Sankey chart is structured
Actuals and comparisons - understanding the numbers used in the Sankey chart

Layout

Step 1: Revenue

The first step is understanding how the company generates revenue. In the StarSchema.co.uk example, revenue comes from two sources:

Step 2: Profit

Next, the chart details all the profit subtotals. An exclamation mark (!) is used to signify the end of each branch in the profit flow:

Step 3: Expenses

This step covers adding in the expense groupings, which reduce profits:

Step 4: Identifying levels

In this stage, we identify each level in the Sankey chart. For instance, in the example, there are six levels. Level 1 includes "B2B revenue → Revenue" and "B2C and other revenue → Revenue."

Step 5: Numbering each relationship and end-point

Finally, we number each relationship and endpoint. Starting from the top of each level, work downwards until all relationships are numbered. For example, in the chart, "B2B revenue → Revenue" is numbered as 1, while "B2C and other revenue → Revenue" is numbered as 2.

Actuals and comparisons

You'll also need to understand the actual and comparison figures which appear on the Sankey chart. The below example shows Year-To-Date (YTD) vs Prior Year (PY) overall:

It's worth documenting the various permunations upfront to ensure a shared understanding; reducing any ambiguity results in a smoother implementation. In the example followed throughout this series, we'll cover a example with 40 different permutations. For each of these 40, there is a Sankey based on standard colours and variance colours, making 80 sankey diagrams in total. The table below shows 3 examples:

Actuals	Comparison	Foreign Exchange Rate
Current Month Actuals	Budget	Actual fx rate
Current Quarter Actuals	Top Down Forecast	Underlying fx rate
Year-To-Date Actuals	Bottom Up Forecast	Fx only

If you’d like to dive deeper into how constant currency reporting works, check out this detailed white paper on the subject: Understanding Constant Currency in Management Reporting.

Conclusion

Now the requirements are understood, you can complete the input tables which form the basis of the solution.