There is a first stage where you get a test (multiple choice) that has three parts. One is numerical, another verbal - both have a style and level similar to a GMAT test - and the third part comprises 5 questions that are small business cases that make you choose where you would put a factory depending on the explanations, or how much money you would need to do a project, etc. The questions in the test change depending on the year and the office, but it is always good to have an uninterested friend go take it so they can tell you about some questions and you can go prepared, since you can only pass the interview with a certain percentage of success in the test.