At most consulting firms, the case study interview will involve a real-life or fictional business scenario that you must problem-solve on the spot in front of your potential employer. The business scenario will likely be one that the firm typically consults on. The aim of this type of interview is not to see how much you know about the market or firm itself, but to uncover what skills and thought processes you use to arrive at your conclusion.
During the case study it’s likely you won’t be given all the information you need at once. Treat the interviewer like a client and ask relevant questions, but don’t be surprised if the interviewer continues to withhold information. They might be testing you to see how you cope and improvise under pressure. In this instance, stay focused and continue to work through the scenario aloud, explaining your processes and reasoning. If you need to make assumptions to move the case forward, articulate exactly what these are.
The fantastic thing about business case questions is that there are often multiple valid solutions. How you arrive at your answer provides more insight for the interviewer than the answer itself.
The analysis of any business case is complex, let alone when you’ve been put on the spot. Here are the most important things for you to think about on the day:
To help you clarify your thoughts (and complete maths sums if need be) make sure you have pen and paper. You don’t want to look unprepared by asking to borrow a pen before the interview has even begun!
Focus! Listen to what is being said and jot down any first impressions or questions you have. When you do formulate questions, make sure they are thoughtful and necessary. Most importantly, remember to listen to the answers you are given. If you become overwhelmed and miss a piece of information, ask for it again.
Be clear about what the problem is that you are being asked to solve. Summarise it back to the interviewer if you need confirmation.
If you have a number of problem-solving techniques up your sleeve, choose which one to use. If you don’t, articulate how you are going to go about solving the problem. You might say, “To begin with I will analyse ‘x’, then ‘y’, and then compare the two”. This provides both the interviewer and yourself with a structure to follow.
Start talking! This part takes some practice, so it’s best to have completed a few mock cases with friends, colleagues or family. Explain the steps you are taking and focus on the reasons why you are taking them. Back-up your choices with logic. Note any assumptions you are making.
You’re being tested on how quickly you can analyse a case and present it on the fly in a high pressure situation. Speak clearly and concisely with confidence and good eye contact. Show the recruiter that you have the skills to communicate with clients of all ages and deliver presentations in a calm manner, despite how you are feeling inside.
You won’t be doing yourself any favours if you rush. If you need a moment to collect your thoughts or even back-track, just ask for it. Having this self awareness, and returning with composure and a clear direction will be looked upon favourably. Work out which pieces of information are important, and what has been put there to bamboozle you. Pay attention to detail and ask more questions if you need further information.
Before putting forward your conclusion, recap how and why you arrived at your solution. Then deliver your conclusion with authority, again showing your capacity to confidently deliver a presentation. You could also mention any areas where you got stuck, and what you might do differently if given the chance.
There are many different types of business scenarios that you might be asked to perform a mock consult on. Here are some of the most common scenarios for you to practice with:
Get together with friends and have a go at practice case studies for different types of questions. The more you practice, the easier they will become.
While nearly all firms like to see how you problem-solve your way through a mock business case, some firms also like to see how you respond to other types of problem-solving situations.
Guesstimates are questions that require you to reach an estimated answer through analytical and logical thinking. They are, as their name suggests, an estimated guess.
Like business cases you’re required to talk through your problem-solving process aloud, however you’re only given a small amount of information so you’re not expected to reach an exact answer. That said, if your answer is not plausible then obviously your common sense will be questioned!
Guesstimates have the potential to throw people off their game due to their seemingly irrelevant nature. You might be interviewing for a technology consulting firm but asked “How many burgers does Red Rooster sell each year?”. It’s no wonder candidates can be caught off guard! In this instance it's vital to forget about the obscurity of the question, and simply focus on solving it.
When working on a guesstimate, it’s handy to follow a similar process to that of the business scenario.
Let’s use the question: How many ping pong balls can fit into a Boeing 747?
Firstly decide and communicate to the interviewer how you will structure your problem-solving process. Begin talking aloud as well as jotting down any maths equations used to analyse the problem. For example, you could estimate L x W x H to roughly gauge the volume of a Boeing 747 cabin. Next, estimate how many ping pong balls fit side by side in a metre line. Now you can cube this number and you have an estimate of ping pong balls per cubic metre. Finally, you can multiply this number by your estimate of the Boeing 747 cabin volume (in cubic metres) to give a guestimate answer to how many ping pongs balls should fit into the plane.
Note that even though your answer will not be exact, you have demonstrated to the interviewer your ability to break down a question into its components, and problem solve with a logical and structured approach.
When completing guesstimate questions, here are a few tips to remember:
Rounding numbers up and down will allow you to work with simple numbers that are easy to calculate. This will help you work faster and with fewer mistakes.
You might be speedy with sums in your head, but if you need to backtrack because the interviewer gives you further information, or because you have found yourself stuck, it’s helpful to have the sums written down.
Be calm, clear and logical, articulate any assumptions, take your time and most importantly explain your reasoning.
Most guesstimate questions are fairly similar. A few examples to practice on are:
Brainteasers are not as common in case study interviews as they once were, but just like guesstimates they have the potential to catch you off-guard. Don’t let this show!
Brainteasers are problems and puzzles that often appear unsolvable at first, but always have a solution - or multiple valid solutions! While some require mathematical skills and logical thinking, others test creativity, lateral thinking and the ability to ‘think outside the box’. Firms are very interested in seeing the latter.
Brainteasers come in the form of questions, riddles or puzzles, and allow the interviewer to see what processes are used to reach an answer when only minimal information is supplied.
There are an infinite number of brainteasers out there! Here are just a few:
A lot of people don’t know where to start when approaching these types of questions. To help get you going, we think it is worthwhile to:
As these questions are designed to fool you, it’s always worth noting your assumptions. This might be an assumption of what the question is asking you to find out, or your assumption of what a word means. For example, did you assume that the third example above was asking for a numerical pattern? Or did you assume that the cabin in the fourth question was a wooden cabin built in the woods?
Once you’ve identified your assumptions, it’s time to think outside the box and find other ways to consider the question. For example, if you assumed there to be a numerical pattern in the third example, what else could be ‘interesting’ about it? If you read the numbers out loud you might discover that they are written in alphabetical order. Likewise in the fourth example, are there any other meanings for the word ‘cabin’? The question could be referring to an aeroplane cabin that fell from the sky, killing the passengers and burning the woods around them.
The answers may not come straight away, but we guarantee that the more stressed you become, the less likely you are to arrive at a possible solution! Take a breath and come at it from a different angle. Think of the bigger picture.
Oh and if you wanted answers to the above examples, here they are:
Regardless of how many case study interviews you are required to do, or whether you are given a business scenario, guesstimate or brainteaser (or all three!), everyone gets stuck at some point or another. It’s almost a rite of passage!
When this happens, either explain to the interviewer that you are going to backtrack, ask a question to gather more information, or simply admit to the interviewer that you are stuck and need assistance. Each of these options is better than losing your composure and confidence! Show initiative by changing the direction of your problem-solving process, and demonstrate flexibility by taking on suggestions that are offered to you. Use this opportunity to impress the interviewer with your capacity to keep it together and deliver a conclusion even when you’re feeling overwhelmed.
And always remember, in a case study interview the firm is more interested in the skills you use to solve problems, navigate challenges and keep yourself together, than your arrival at the ‘perfect’ solution.