Visualization: A waterfall chart is a waterfall chart is a waterfall chart …
SP4 for SAP BO Dashboards (Xcelsius) contains the waterfall chart as a new component. At last a waterfall out-of-the-box, eagerly awaited by many customers. It does not fulfill my requirements. But it does not have to as our graphomate add-on contains a wonderful waterfall.
Why our graphomate waterfall chart stands out against the standard waterfall is what I want to describe in this article.
But at first: When is a waterfall the chart of choice?
In principle, a waterfall chart shows the cumulative change between an initial and a final value. The whole change is dismantled in its positive and negative components, which are depicted with stacks in a slightly shifted position. It is maybe because of this stairs-like depiction from which the chart got its name waterfall chart. Other names are flying bricks chart or Mario chart (as the suspension of bricks in mid-air reminds of the popular game) or, in finance, a bridge. Another common English term is Cascade Chart.
The changed positions are often shown in red or green.
Due to its focus on changes, the waterfall chart is especially suitable for portfolio analysis (warehousing, Cash-flow statement) or profitability analysis.
This is a simple waterfall chart for the analysis of inventory changes over time:
In his blog article “Xcelsius 2008 SP4 – waterfall chart”, Greg Wayne shows an example of a waterfall created with SAP BO Dashboards (Xcelsius) which I want to use as starting point for my further analysis. It is very suitable to expose some of the vagaries in SAP BO Dashboards (Xcelsius) which may diminish the meaningfulness of the waterfall chart. And furthermore, it displays a profit and loss statement, which, in my opinion, should always be presented in waterfall charts.
So, what do we have to grumble about here? It is a beautiful waterfall, isn’t?
Let us take a further look at the chart:
- The value axis starts at $100K. Therefore, the first and last column is too short. A visual comparison is impossible because the proportions are no longer correct.
- The value axis is shown and the columns are labeled; better be safe than sorry? Or maybe the value axis is shown in fairness to the reader, because it has been cut off?
- And is it really necessary to have 6-digits data labels?
- The help lines are also unnecessary and in fact make it more difficult to understand the chart as the connecting lines between the columns are missing. The columns seem to float around in Cartesian space. For me, it is difficult to localize the initial and final value of the changes.
- What does “total” mean?
- And, at long last, the chart does not comply with our paradigm to show comparisons in structure – and when all is said and done, a profit and loss statement is nothing else- in a horizontal oriented way.
Greg relied on the standard parameters of SAP BO Dashboards (Xcelsius). The result is, from the perspective of a friend of good visualization, rather disappointing. Take a look at the vagaries again in this visual summary:
I am a strong advocate of the SUCCESS rules for a successful business communication. I especially like compressed depictions and try to show as many business figures as possible in the given space. This is the content of the CONDENSE rule. How would I show the profit and loss statement done by Greg with the graphomate addon on the same real estate?
What is different?
- The chart is smaller without having impact on the legibility!
- Due to the horizontal alignment I can better compare the individual factors involved – without turning my head 90° degrees to the left,
- the colors red and green are used for deviations, therefore the waterfall is formatted in shades of grey,
- thin lines connecting the bars: I think these lines help to make it clear that the starting point for the next change is where the last bar ended,
- Are costs negative or do they only have a negative effect on the result?
I don’t think that costs are negative, but this is controllable with our graphomate add-on,
- absolute and percentage deviation charts enable you to compare the values with the previous year,
- axes are labeled and, in addition, the axes itself support the interpretation of the data with their colors: black means actual year, grey means deviation to the previous year – more about this later,
- a so-called “scaling helper” – the orange area – supports the beholder in the evaluation of different gradations in charts, which are unavoidable sometimes. Scaling from my point of view is on of the greatest challenges in building fast readable dashboards.
I build this chart in SAP BO Dasshboards (Xcelsius) with our graphomate add-on within 2 minutes and of course you can align it horizontally with just one click – like the waterfall in Fig. 1.
I want to show an example for a profit and loss statement taken from “real life”. It has also been realized with graphomate and uses another feature: we can use as many subtotals in a waterfall chart as we like.
Source: SAP Annual Report 2010, S. 166
The chart is a visualization of the consolidated financial statement according to IFRS (International Financial Reporting Standards) for the SAP group for the year 2010, realized with graphomate addons. I am particularly proud of the third waterfall chart with the absolute deviations in comparison to the previous year. Really 🙂 I am much obliged to Rolf Hichert, who had the idea for this. And it was his ideas for good reports and presentations which build the basis for his SUCCESS rules.
In the following version 1.3 of our add-on coming this month we will introduce spans in a waterfall, so that you can, for example, show the total costs as a floating bar.
… and now for something completely different! No, not HTML5, still waterfalls 🙂
Does anybody remember the song “waterfall” from the stone roses? … be careful: this melody won’t leave your head.
Keep on singing, Lars