Cases fall into three types: business, estimation, and interpersonal.
Business case: Here, the interviewer describes the business situation of an industry or a firm and asks for your analysis. The case may be based on general strategic issues, or it may focus on specific questions, such as how to make distribution more effective, or what to focus on in new product development.
Estimation case: In an estimation case, you must estimate a quantity that you could not possibly know in advance, or show you can apply a known framework to solving such an issue. For example, you might be asked to estimate the number of meals being served in London at any given time, or the number of roads leading to Nairobi.
Interpersonal case: In an interpersonal case, your actual or expected behaviour in a specific situation is discussed. The situation could either be an example you have described earlier in the interview (for example, an example of a difficult team setting) or a situation described by the interviewer.
There are not only great differences in the types of cases I encountered in my job search, but also in the way they were presented. In most cases, it happened quietly and calmly in dialogue. But in one case, I was hard pressed by the interviewer and was tested on structure and reactions in a high-pressure situation.” ( Henrik, Consultant )
Business and estimation cases are the most common in consulting interviews. Usually, hybrids are used: a business case often includes an estimation case, and an estimation case may become a fully-fledged business case. A casual question about your previous employment can turn into a case. Or, during a process case, you may be asked to complete a small estimation case.
Each case type tests your ability to present and , along with other qualifications.
Business cases are usually designed to test your level of business understanding and your ability to handle numerical and multiple pieces of information. They also test how well you identify, structure and prioritise important issues based on logic and, possibly, a relevant framework.
Estimation cases mainly test how well you logically work through a mathematical problem, make reasonable and well-founded assumptions and perform basic calculations comfortably and accurately. Remember that many consultants are hired every year who have had few quantitatively-oriented courses: we are simply looking for reasonable familiarity with basic mathematical and estimation problems.
Interpersonal cases are often used to gain an impression of how you will behave in a work setting – either on the team or in a client situation. The case is sometimes used for getting additional input on how well you would fit into the company culture. The case is typically constructed to allow a discussion about how you work with internal and external parties (colleagues and customers) based on a description of a specific situation and a question about how you would react.
The cases you will meet in an interview are usually related to the work and responsibility you are expected to handle at entry level. However, there are also the ‘odd one out’ cases such as brainteasers. They are usually short questions that test your logical sense or your ability to think “out of the box.”
But remember! Cases can go anywhere. Because there usually is no one right answer, cases can take you down unexpected or unknown roads. The important thing is not the result you reach, but the path you choose to go there and the way you interact with the interviewer in the process.