Case interviews are the main selection method for a consultancy firm's applicant process. Many firms will have a two or three-stage process to land a full-time job, at least one of which will involve a case study. This is a chance to show your analytical, reasoning and communication skills and involve a hypothetical business or organisationsal challenge that could be faced.
The format, length and number of case study questions will vary for different firms, but they typically will be a one-to-one interview, followed by competency-based questions.
Why are Case Studies used?
Case studies are used to assess a range of skills which can broadly be summarised as your “commercial skill set”. For consulting case studies, this will typically be assessing your ability to solve business problems in a structured, logical fashion, making reasonable commercial assumptions as you go along and using your mental maths ability to synthesise these assumptions to find the answer. Note that they are not looking for a “right answer”; they are looking for a “right method”.
Types of case studies
Different industries need to test different skills. So, depending on whether you’re applying to management consultancies, strategy consultancies or investment banking, your case study will be slightly different. There will be different approaches for each of the following:
How to answer the case study
Here we will focus on the consulting type case studies. There are four steps that will greatly increase your chances of success by helping you to structure your answer in an intelligent and commercially aware fashion.
The Ivy Case is a system created by a Harvard professor who coached students for interviews at top-tier consultancies such as McKinsey. He summarised that all case studies were a combination of the following 12:
Strategy Cases: Entering a new market, Industry Analysis, Mergers and Acquisitions, Developing a New Product, Pricing Strategies, Growth Strategies, Starting a New Business & Competitive Response.
Operational Cases: Operations Case, Increasing Sales, Reducing Costs, Improving the Bottom Line, Turnarounds.
To get it right, here is the top line method for structuring your case study:
1) Summarise the question: Often the interviewer will give you a lot of excess verbiage to test your ability to see into the heart of the problem. The most important thing to ensure you start down the right path is for you to summarise and confirm the question with the interviewer.
2) Verify the objective: The first thing consultants do with clients is to define what “success” looks like to that client and to find out why that is the case. If the objective is “to increase profits”, ask questions such as: why is this important? And in what timeframe? Is there anything else we need to know? By asking these questions, it will not only show your sensitivity to the case and it could also uncover vital information.
3) Ask clarifying questions: Very often the interviewer won’t provide all the necessary information to answer the question and it is up to you to find out this information before answering the question. Are we figuring out the profit per day, per month or per year? Is it for one store or all the stores? Of course, there is a limit to the number of questions you should ask but you must ensure you have the relevant information to make sensible assumptions.
4) Layout your structure: Now that you know exactly what they are looking for you can begin to tell them how you find the answer. Once you have laid out the structure, you can begin to add your assumptions into the formula and use your mental maths to come up with a well thought out answer.
5) Follow the structure to come to your conclusion: It's important that you follow the steps you announced in 4). An easy way to come up with a logical structure is to memorise The Ivy Case – a set of 12 types of case studies and how to solve them. By following this, you won’t forget any elements and your answer will be concise and well-structured.
Tip: Making sensible assumptions
This is potentially one of the hardest parts to get right as it requires you to make a sufficiently detailed assumption without making it too complex that you will not be able to do the mental maths correctly to come to the right answer.
For example, if you needed to estimate the price of a coffee at a coffee shop in order to find out their revenue, a sensible assumption is £2, not £10 even if counting in multiples of 10 is easier. At the same time, £1.19 is probably not the best choice, even if it is more accurate because it will be harder when you come to using your mental maths.
Tip: Practice, practice, practice…
Finally, reading this article is a good first step to being successful in your case study but practice will be what makes the difference between a job offer or not. By practising the relevant case studies above and using the tips on structure, you will increase your success rate in case studies and feel more comfortable on the day.