A step into the world of consulting is a step onto the path of ceaseless learning. No other industry is as diverse and widespread in the fields that they deal with. It comes as no surprise that the recruitment process is accordingly very thorough and extraordinarily challenging. Even individuals with impeccable academic credentials may falter at the challenge of a case interview.
Your knowledge and character will be put to the test
Recruiters will push you to your limits, put you into unconventional situations and force you to think on your feet. After all, you are a candidate for working with some of the best brains in the industry. You will be tested in multiple interviews, with the smallest details making the difference between advancing to the next round and being ousted.
How do I keep my cool and not crack under the pressure? What framework is best suited to structure my thoughts for this particular case? These are the kind of questions the PrepLounge community can give unparalleled insights into.
The tips contained here are compiled by our most experienced consultants and will bring you closer to a job in consulting. You will need to invest a vast amount of time into preparation, there is simply no way around it, but with the help of our tips you can make your case preparation as efficient and effective as possible. However, before delving into this area, it is important to understand the nature and fundamental components of what a case interview is and why they are conducted.
- Case Interviews: What you need to know
- What is a case interview?
- Why are case interviews conducted?
- Skills required in a consulting interview
- The Case Interview Format: What challenges await you
- Difference between first and second round interviews
- The different case types
- Case interview examples
- How to crack any type of case study in 10 steps
- How to prepare for a case interview
- PrepLounge: The key to your success
A case interview is part of the job interview process in consulting in which you as the candidate have to analyze and solve a problematic business scenario while interacting with the interviewer. The case study is often based on a problem the interviewer has worked on in real life.
During the interview, you will have time to solve the question and will subsequently need to present your findings. This part of the interview is intended to be more of a dialogue. You will need to be proactive and ask questions when attempting to close in on the correct conclusion. Oftentimes the consultant will attempt to guide you into the correct direction by asking questions himself. A case can be interviewer-led or candidate-led. Our BootCamp deals extensively with the differences between interviewer-led cases and candidate-led cases.
First and foremost, consultancies utilize case interviews with the intention of probing the quantitative and qualitative skills of an applicant that are required for a good management consultant. The way you present yourself and apply the limited amount of information given to you will also be analyzed as these represent crucial qualities of any aspiring consultant. The reason for the prevalence of the case interview format is that the topics and themes handled in most cases reflect conditions close to the reality of the day-to-day activities of a consultancy. It requires the applicant to ask the right questions, apply structured frameworks and think out-of-the-box.
A case interview has no “correct” or “standard” answer. There are often many solutions to a single case which may differ from the interviewer’s expectations. In the end, what counts is your train of thought and how you got to your solution. The interviewer will evaluate you across five main areas:
Problem solving skills
You will be analyzed on your ability to identify problems, isolate causes and prioritize issues. During a case interview you will be presented with a wide range of relevant and irrelevant data pieces. You must know how to use this data to make your recommendations. You have to prove that you are able to construct a logic argumentation without rushing to conclusions based on insufficient evidence.
Creativity and business sense skills
As a consulting candidate, you should know the basic business concepts as well as show a certain amount of business sense and creativity. If the interviewer asks you to find innovative ideas to increase profitability of a hotel chain, you will have to come up with a range of ideas that make business sense. You are not expected to have deep knowledge on the hospitality industry, but to be able to ask relevant and insightful questions on the aspects important for you to solve the client’s issue at hand.
Maintaining a structure means that you solve the question with a clear step-by-step approach that you communicate actively towards your interviewer. A good structure is the most important part of a case interview as it is the underlying base of your whole approach and argumentation. It is also the main reasons why candidates fail their case interview. A common mistake that candidates make is that they try to apply standardized frameworks to any case they are given. Instead, you should solve each case by creating a framework specifically tailored to its needs – as you would do as a consultant on the job.
As a consultant, part of your job is number crunching and interpreting data. Therefore, it is important that you have a good feeling for numbers and have great mental math skills. You should be able to perform simple calculations in your sleep.
In times of digitalization the soft skills become more and more important for management consultants. On the job, you will be in contact with high-level CEOs, clients, partners and colleagues. Strong communication is crucial for you to get your work done efficiently. Thus, your interviewer will pay close attention to the way you communicate and present yourself during your conversation. Always be professional, answer concisely and communicate the key message first (see Pyramid Principle).
During the entire application process, you will partake in up to six case interviews in two rounds or more. This is dependent on the position you are applying for. Most case interviews have the same underlying structure. An individual case interview may take up to an hour and usually consists of four parts:
- ~ 5 minutes: Introduction and small talk
- ~ 15 minutes: Personal Fit Interview
- ~ 30 minutes: Case Interview
- ~ 5 minutes: Your questions to the interview
While the format of the first and second round interview stays the same, the seniority level of the interviewer differs. The person interviewing you in the first round is usually more junior having up to four years of consulting experience (Associates or Engagement Managers). The second round is led by Partners who have more than ten years of experience and tend to drill you in order to understand how you cope with challenges. Therefore, second rounds are perceived as more difficult by candidates. Since partners have a stronger voice when discussing an applicant, your performance during the second round of case interview carries also more weight.
The three core types of cases you will be confronted with are business cases, estimating cases and brain teasers. All three types of cases will require a sophisticated approach and a comprehensive analysis.
A business case usually revolves around the estimation of a company’s profitability and investment opportunities. This type of case portraits a business problem that requires solving. Estimation cases (also known as market sizing cases) pose a similar challenge. Here you will need to evaluate the potential and profitability of a certain market or a specific product. Brain teasers are usually a riddle which will need an out-of-the-box approach to solve. However: It’s important to not get hung up too much on the frame of the interview.
Here are some simplified examples of case interview questions:
- Bain & Company Case “Old Winery”: You have inherited the “Old Winery” from your grandfather, a winery which has been family owned for five generations and can be dated back to the 16th century. Due to the not so well-known brand, the demand for the “Old Winery” wine is currently rather low. You do not intent to run the winery operatively, given your limited knowledge of wine making, but you find the idea of owning a winery exciting. Your plan is to give the winery some fresh impetus.
- Roland Berger Case “Onlinestar”: Onlinestar, an online retailer of furniture and garden products (core business), has grown significantly in recent years as a result of an expansion of its product portfolio. Despite expansion, the financial ratios have deteriorated in recent years. Gross profit margin decreased significantly. Against the background of expected stagnating sales for the current financial year, short-term action is required. The board of Onlinestar asks you for an analysis of the reasons for the negative result as well as a derived recommendation for action. In addition, the management board would like to receive a sales and gross profit plan from you for the current financial year.
- Oliver Wyman Case “Full Electrons Ahead”: Your client, large automotive OEM WyCar, has developed its first fully electric vehicle (EV) and introduced it as a pilot on the Austrian market last year. However, sales have been far below the expected numbers. The management has engaged you to support them in understanding the reasons and advise them on how to adjust the product offering.
- Deloitte Consulting Case “Footloose”: Duraflex is a German footwear company with annual men’s footwear sales of approximately €1 b. They have always relied on the boot market for the majority of their volume. Now one of Duraflex’s competitiors launched a new line of aggressively priced work boots. The strong success of this line has caused Duraflex’s management to re-evaluate their position in work boots. The management team approached you and asked for your advice. In order to advise them on their future work boot strategy please prepare first some insights regarding market size and competitive landscape.
- PrepLounge Case “Airport Taxi”: Dubai Airport has decided to counter the chaos in the airport taxi service by commencing a bidding process to assign airport taxi services to 3 operators only. They are retracting all existing permits and are issuing 2,100 new permits to the three largest operators in the country. Our client is a local Big-three taxi operator with a 3,000 car fleet, but he is not servicing the airport yet. He has a spare capacity of 500 taxis and he is considering applying for 500 new permits, but he doesn’t know if he will get a positive return on his investment. He asked us to help him determine if he should pursue applying for the permits or not.
You can find more than 150 case studies in our Case Library!
Case Interview Secrets: 13 Vital tips for your actual case interview
- Tip 1: Focus on the task at hand
- Tip 2: Ask the right questions
- Tip 3: Buy time with repetitions
- Tip 4: Only form a hypothesis with sufficient information
- Tip 5: Utilize data for your analysis
- Tip 6: Take clear notes
- Tip 7: Structure is key
- Tip 8: Don't force-fit frameworks
- Tip 9: Don’t panic if you get stuck
- Tip 10: Sometimes there is no clear answer
- Tip 11: Engage the interviewer
- Tip 12: Be confident
- Tip 13: When in doubt, reschedule
Don’t think too much about the approach your interviewer is taking. It should not matter if the conversation is interviewer-led or candidate-led. If you go into your interview with a profound understanding on how to handle even a difficult case, the format of the interview shouldn’t be an issue. Keep a cool head and structure your thoughts.
At the beginning of the case, your interviewer will present you the situation of the client. Don’t rush into the analysis without developing a deep understanding of the problem first. Ask your interviewer questions in order to clarify the case. This is expected behavior that also takes place later with the client. Make sure you understand what the business model and your objective in the respective case are (regarding both money and the timeline). If there are any other possible limitations you are unsure about, ask your interviewer in a concise way. Asking unnecessary questions will raise doubts about your ability to work efficiently under pressure.
A common trick consultants use is the repeating of facts or overall goals. By doing this you’re showing a fundamental comprehension of the case and emitting an aura of control, gradually heading towards a solution. This technique can give you more time to think. Articulating the facts of the case can also be a source of clarity and allow you to more quickly form solutions.
Do not state a hypothesis at the beginning, a stage in which you may still have incomplete information. Get a good sense of the case’s environment and ask sensible follow-up questions. Only then frame a structure and formulate a hypothesis.
Taking wild guesses is a death sentence for your case interview. Make sure your claims are backed up by the facts and remain calm when presented with new information. Consultancies will closely observe how you make use of new data and incorporate it into your hypothesis.
Taking structured notes is a highly underrated skill when dealing with a case. Making sure your notes are coherent and clear will make your thoughts easy to navigate and ensure you don’t lose your footing during the interview. Place your sheet horizontally in order to maximize your space and jot down the case’s key question on the left side of the page. This way you will never lose sight of the main objective. The remaining portion will be dedicated to the issue tree, with your hypothesis included above the issue tree.
Make sure that you highlight key pieces of information that add substance to your hypothesis. When it comes to calculations, use a separate page but practice having it organized in case you need to go back through your assumptions or calculations. Try to limit the number of pages you use to maximum three sheets. Otherwise, you will stress yourself out while trying to find what you are looking for.
The most important aspect during a case interview is having a good structure. You can structure your case by following these four steps:
- Craft an issue tree as the overall foundation for your structure. This is a customizable framework used to analyze the root causes of problems in a case. It helps you to break a complex problem down into its components.
- Make sure that your issue tree is MECE to avoid inefficient dependencies between branches that will slow down your analysis. MECE is a way of segmenting information into sub-elements that are mutually exclusive and collectively exhaustive.
- Prioritize and concentrate on high impact issues of your issue tree that will create value for your client. Always make sure you explain the reasons behind your choices to the interviewer.
- Use the Pyramid Principle to structure your conclusion, a three-step structure to present your synthesis in an effective and convincing manner. First, state the recommendation (What?). Second, provide three reasons supported by data (Why?). Third, provide information on how to implement the recommendation (How?).
Standard frameworks can be a source of inspiration but should never be force-fitted to a case. They are very stiff and do not allow room for customization. If you use pre-defined frameworks, you run the risk of missing important elements of the specific problem you are trying to solve. A consultant would not just force-fit frameworks to their specific client’s problem, so you should not do this in your case interview, either. Each case is unique and requires an individual customized framework that is MECE as well as adapted to the problem you are trying to solve, the company and the industry.
If you ever get stuck, don’t freak out – it happens. What counts is how you deal with the situation. Here is what you can do:
- Take a deep breath or a sip of water if you have a glass of water nearby.
- Take a moment to grasp the big picture, to recap what you have learned so far and what you still need to find out in order to address the main question at hand.
- Outline how these sub questions can be answered, and what kind of data or information you will need to do that.
- Double check whether data or information provided by the interviewer at an earlier stage is now getting new relevance.
- Think out loud and take the interviewer along your thinking process. If you are puzzled by some obvious contradiction, actively discuss this with your interviewer. Oftentimes an interviewer will wait for you to explicitly verbalize your confusion before gently giving you guidance.
Usually a case interview has no “correct” or “standard” answer. The case may encompass you exploring the issues and walking down several paths. There may be many solutions to a single case which may differ from the interviewer’s expectations. In the end, what counts is your train of thought and how you got to your solution. You are not expected to know everything about business but demonstrate a logical judgment and a good approach to solve problems.
Nevertheless, you should always give a clear recommendation at the end of the interview when the interviewer will ask for your conclusion. The trick is to use supporting arguments based on what you have learned during the analysis, to point out limitations and to also highlight additional areas to explore in order to confirm that your current understanding is the right one.
The interview should be a dialogue, so make sure to engage the interviewer and demonstrate not only your business judgment, but also your communication and people skills. This gives a first insight on how you might interact with future clients and colleagues. How can you do that?
- Explain. Share your thought process with the interviewer and always let them know what your next steps are.
- Listen. During your case interview, the interviewer will usually give you hints and steer you in a direction. Notice that! If they ask a specific question, e.g. “Name three points about…”, answering in two or five points will mean that you didn’t pay attention.
- Ask questions. Create a discussion, initiate small talk and use your chance to make a positive connection with the interviewer, especially at the end of every interview when you get to ask final questions. Find a point in common and try to stand out. Here is a list of best questions to ask at the end of an interview.
You don’t necessarily need to be extroverted to be a top management consultant, but you need to be confident. Consulting is a people job as much as it is an analytical job. It is important for the client to feel that you know what you are doing. Thus, this is something the interviewer will take into consideration. Here are five things you can do during the interview in order to come across as more confident:
- Try to enjoy the interview by focusing on the challenge, the satisfaction it brings you when you solve the case and the joy of sharing your life experiences with someone else. If you have fun, chances are high that the interviewer has fun, as well.
- Find your own style and don’t try to pretend to be someone that you are not. It is fine if you are not the most outgoing person. Just be genuine!
- Sit up straight, but don’t be too stiff. Push your back against the back of the seat and don’t just sit on the edge of the chair.
- Make eye contact, but don’t stare, either.
- Speak in a clear, calm and unrushed manner. Don't mumble or whisper but equally don't shout. Think before you speak!
If you’re not feeling confident about your chances, don’t hesitate to reschedule. If you take this course of action, take a few things into consideration. Make sure to suggest an alternative day and avoid rescheduling multiple times at all costs. The consultancy will be grateful for you suggesting an immediate alternative. Try to be transparent as to why you are rescheduling without going too deeply into details. However, rescheduling should only be used as a last resort.
Step 1: Listen actively and take notes. Write down every piece of information, especially numerical data.
Step 2: Restate the question. Pause, paraphrase and make sure you understand the problem statement by confirming with the interviewer.
Step 3: Clarify the objectives and identify the problem. Ask specific questions and double check on objectives. Make sure you completely understand the problem.
Step 4: Write out your structure. Ask your interviewer for a minute to prepare your structure and organize your notes. Identify your case type and use an issue tree to customize your structure. The branches of your issue tree should be MECE.
Step 5: State your hypothesis. Now that you have set up the issue tree, your task is to test each branch to see if it is the root-cause of the problem. Where to begin? A hypothesis based on an educated guess helps here. (e.g. "Since you have mentioned that revenues are more or less flat, my hypothesis is that the problem is mostly driven by the cost side of the business. If it is okay with you, I will start by […]")
Step 6: Think out loud. Sharing your thoughts allows the interviewer to interact. Refine or rebuild your hypothesis as you find out more.
Step 7: Gather more data in order to test your hypothesis. Proactively ask for relevant data and always segment it (e.g. using the ABC analysis). Try to evaluate whether trends have been company-specific or industry-wide.
Step 8: Dig deeper while staying structured (MECE!) throughout the case. Always refer to the structure you have set up at the beginning of the case but be flexible as the case evolves. If you conclude that your hypothesis is false, eliminate that branch and go to the next one. Summarize findings when switching major branches. If your test confirms your hypothesis, go deeper into that branch, and drill down to the lower levels until you identify all proven root-causes.
Step 9: Choose a recommendation and use the Pyramid Principle to structure your conclusion. Ask for a minute to gather your thoughts and then state your recommendation. You need to deliver a one minute, top-down, concise, structured, clear and fact-based summary of your findings.
Step 10: Stand by your conclusion. Your interviewer will likely challenge your recommendation (either to see if you can handle pressure or to assess if you really believe in what you are saying).
How to prepare for a case interview
- Tip 1: Learn the theory
- Tip 2: Gradually develop your business intuition
- Tip 3: Bring your mental math up to speed
- Tip 4: Practice makes perfect
- Tip 5: Get support from experts
- Tip 6: Learn and keep track of your progress
- Tip 7: Don’t forget about the personal fit
- Tip 8: Practice confidence
- Tip 9: Take breaks
By reading this article, you have already taken the first step of getting to know what case interviews are all about. Well done! You can now proceed by learning the theory you need to know to solve them. In general, you should learn how to:
- Identify your case type (e.g. Market sizing, Market entry, Profitability, Growth)
- Structure your thoughts (e.g. Issue tree, MECE, Pyramid principle)
- Use business analysis tools (e.g. ABC analysis, Breakeven, Benchmarking)
- Define common terms of business (e.g. NPV, CAGR">CAGR, Fixed and variable cost)
As you need to have a good business sense to successfully pass your case interview, you should dedicate some time before to gradually build up your business intuition. The earlier you start doing this, the easier it will come to you. All you have to do is make it a habit of regularly reading business publications or magazines. You can choose new insights by McKinsey, Bain and BCG or find other sources that appeal to you. While you do that, try to develop a basic knowledge of business, strategy and industries, such as retail, airlines, telecom, banking, natural resources and tech.
All case interviews involve doing math without a calculator which is why brushing up your math skills should be a constant part of your daily prep plan. Practice until you are a hundred percent comfortable doing basic additions, subtractions, divisions, multiplications and growth rate calculations in your head. Read our article on Fast Math and make use of our mental math tool in order to practice your efficiency. This will greatly ease the pressure if confronted with a math problem in your interview.
Knowing the shortcuts for a wide range of calculations will help you simplify math problems. For example, break down complex math problems into multiple smaller operations:
97 x 53
= (100 - 3) x (50 + 3)
= 5000 + 300 - 150 - 9
Take a look at our vast Case Library with which you’ll be prepared for all possible case types. Our case collection includes cases which have been used in case interviews in the past. Solving cases on your own can give you a first feeling for them, but the only way to improve the skills you need to pass your interview is to put yourself in a case interview situation. Find a few outstanding candidates you can practice with and practice cases on a regular basis. The more perspectives you can get, the better. Feedback will help you improve.
On PrepLounge, the world’s largest case interview community awaits you. Simply schedule or accept a mock interview with another candidate on our Meeting Board! Here is how it works:
- Schedule: After you and your case partner have confirmed the mock interview on the Meeting Board, your meeting is set and should be visible on your dashboard.
- Communication: We recommend you to directly get in touch with your case partner to confirm your method of communication during the interview (e.g. Skype) and case preferences.
- Interview: During the back-to-back meeting you will take turns with your case partner in order to play both interviewer and interviewee roles. Don’t neglect the part of the session where you play the interviewer role. It will help you notice points of importance and adapt your approach accordingly.
- Case: There will be two PrepLounge cases randomly selected by default, but you can also change them and pick one of our other 140+ cases or use your own case.
- Feedback: This is the most important part of your mock interview as it helps you to improve your case performance. Please give valuable feedback to your case partner. You would want them to do the same!
To make your case interview preparation as effective as possible, we recommend you to also invest in coaching sessions with experienced top consultants. Our experience shows that this will be worth it, as it significantly increases your chance of getting your dream job offer (by four to be exact). Our experts know exactly what interviewers want and can work with you on every aspect of your case performance, whether it is structure, personal fit, confidence or communication. They can even give you valuable networking tips and help you getting a referral.
We offer you a transparent list of all experts, including their professional and educational backgrounds, top skills, individual approaches, reviews and recommendation rates. This allows you to individually choose the perfect experts for your coaching sessions. You may also benefit from our CoachingPlus package that comes with an overall discount.
You can do as many cases as you like, but if you do not learn from them, you will not be going to improve your case performance. This is why you should do the following: At the end of each case that you solve, whether it is on your own, with a case partner or expert, write down in your own words what mistakes you have made and what you learned. After a few days, redo the case and apply your learnings to ensure that you are making progress. Keeping track of your improvements will keep you motivated and make sure that you don’t repeat the same mistakes.
It doesn’t matter how much you ace the case, but if you are not a personal fit to the company, you will not get the job offer. After all, consulting is a people’s business, that includes teamwork and spending a lot of time with your colleagues. In order to ace the personal fit part of the interview, it is important that you understand what any interviewer is looking for in a candidate to decide that he or she is a personal fit. Typically, the interviewer has three primary questions in mind.
Then, you have to learn how to convey to the interviewer that you comply with what he or she is looking for. Practice your answers to the personal fit part with other candidates or experts. Use our Self Study Mode to test yourself and learn from other best practice answers to typical questions like:
- Why management consulting?
- Why company x?
- Why should we hire you?
- Tell me about yourself!
- Give me an example of a time that you have led a group to achieve a difficult goal!
- Find more questions in our free Self Study Mode!
The more you practice, the more confident you will automatically feel. However, feeling confident is not equal seeming confident. Sometimes you can come across as insecure without even noticing and this can be due to minor communication style habits. Therefore, you should ask your PrepLounge case partner or expert to take your verbal and non-verbal communication into account and to give you feedback on your level of confidence or insecurity. Try to focus on the following aspects during your practice:
- Sound of your voice. A monotone voice or speaking too fast gives an impression of insecurity and a poor communication style. To avoid that, you can listen to podcasts with great speakers for about 30 minutes to one hour per day. After a couple of days, you will start to speak in a similar manner, as you will absorb their communication style.
- Smile. Smiling can be a powerful element to show that you enjoy the interview (and interviewer) and are not afraid. You can force smiles (obviously not too much) in case you get feedback that you seem too serious.
- Eye contact. You do not need to constantly look the interviewer in the eyes, but you should not look away when he or she asks you something and you should not stare, either.
- Ability to break the ice. Confident people are not afraid to start small talks with interviewers from the beginning. Keeping silence create less connection and may be considered a sign of lack of confidence.
- Posture. You should try to keep straight in the chair most of the time. Leaning too much towards the interviewer can be seen as a lack of confidence.
In total you should prepare for well over 50 hours in an up to 6-week time period, practicing on a daily basis. This can be exhausting, and we know that a lot of candidates struggle with lack of motivation and focus, especially after an intense period of case prep. This is usually because they forgot to implement regular breaks in their prep plan. Professional athletes will always take time to rest to give their muscles time to regenerate, and so should you for your brain muscle. A good strategy is to develop an evening and morning routine that gives you time to relax and maximizes your energy level for the prep during the day. Here are some examples of what you can do:
- 15-20 minutes exercise in the morning or evening
- A cold shower in the morning
- Meditation or writing a journal
- Define three important things to do for the next day and allocate the time for all activities while doing the most important ones first
- No social media one hour after you wake up and before you go to sleep
- Get enough sleep (at least 7 hours)
- Take breaks between each case or intense case practice session and do something totally different (e.g. workout, play video games)
In order to become the best, you must learn from the best. That is exactly what PrepLounge can offer you. Among our ranks are former consultants who themselves aced and, in some cases, even helped shape the application process at their respective firm. These PrepLounge Experts hail from the most revered consultancies the industry has to offer - from Bain to McKinsey - and are uniquely qualified to give PrepLounge users insight into the mastery of a case interview. The vast PrepLounge community makes it easy to find case partners. Whether you are looking for a professional case coach or other aspiring consultants, you will have no problem finding case partners in the buildup to your interview.
Apart from case partners from every imaginable background, PrepLounge provides a colossal collection of online resources to give you the best preparation leading up to your case interview. We’ll provide you with questions and answers to the most important consulting case types and share in-depth knowledge for the best possible case interview preparation. You will be able to find case partners to practice online and always be on top of the latest insights and news regarding consulting jobs and top consulting firms.
As a PrepLounge user you will receive access to all these perks. PrepLounge will accompany you all the way from your application through to your contract negotiation. You strongly diminish your chance of success without sufficient preparation. Invest into your future and give yourself the best chance at acing your case interview! Exchange your experience with peers from all around the world in our Consulting Q&A. Join our case interview community today and embark on your journey into consulting!