A tree visualises the composition (or decomposition) of a number into a number of factors. They are what I call ponder charts, not to be presented during a TED talk, but rather they are useful for (complex) studying relationships between different factors.
Below are two examples of these analysis trees. The first is a summary profit and loss account for a company. I often use these a tree like this to visualise the business model of a startup by forcing a forecast year 5 P&L of a success scenario into this format. It is impossible to forecast the future accurately, and investors and founders will always disagree on the numbers, but the tree teaches you how to think about this company. What drives its economics? What would you have to believe for the year 5 scenario to be true? A tree always has to add up and multiply, this often leads to insights when it forces you to fill in boxes that you did not originally take into account (i.e., you forecast your sales, you assume market size, and right in the middle sits your implied market share).
A second example is this return on invested capital tree. It explains how (and more importantly, why) company performance is changing over the years. In this version I added miniature line diagrams to make the annual trends clearer. PowerPoint cuts the vertical axes of these graphs automatically, amplifying the trends in the line graph. Normally, I would object to this form of lying with statistics, but in this case with the very small diagrams, it is actually useful.
Both these trees go from left to right, sticking to the McKinsey style of going from big picture to detail.
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