[2] According to professor of strategy Arnaud Chevallier, elaborating an approach used at McKinsey & Company,[3] there are two types of issue trees: diagnostic ones and solution ones.
[4] Diagnostic trees break down a "why" key question, identifying all the possible root causes for the problem.
Solution trees break down a "how" key question, identifying all the possible alternatives to fix the problem.
[6] Issue trees are used to answer questions in case interviews for management consulting positions.
[7] A quantitative type of question, the market sizing question, requires the interviewee to estimate the size of a data group such as a specific segment of a population, an amount of objects, a company's revenues, or similar.