A Comprehensive Guide to Case Interview Prep [tips updated 2021]
- Last Updated December, 2021
Rebecca Smith-Allen
Former McKinsey Engagement Manager
Table of Contents
What Are the Best Ways to Prepare for Interviews with Management Consulting Firms?
Congratulations!
If you’re on this page, you’re probably considering a career in management consulting or are already in the middle of the interview process.
We’re here to help.
We’re a team of more than 20 former McKinsey, Bain, and BCG consultants and recruiters (our average time in consulting is 13 years each) and we put together this guide to help you prepare for getting your consulting offer.
After reading this, we hope “congratulations” is also what you’ll hear when you leave your final interviews.
Management Consulting Jobs Are in High Demand
Management consulting jobs are among the most sought-after positions in on-campus recruiting, whether you’re applying as an undergraduate or from a business school.
Consulting firm recruits also include law school students, Ph.D. program candidates and people who’ve already started their professional careers in other industries.
Why?
Management consulting firms are filled with smart, driven people working to solve hard business problems.
This work is a great launching pad for your career.
Top consultancies offer competitive salaries and also invest significantly in employee development. A job at a management consulting firm will expose you to multiple different industries and types of business problems.
There’s a lot to like about a career in consulting!
Competition for Jobs with Top Consulting Firms Is Fierce, so Preparation Is Essential.
But attractive jobs are usually highly competitive, and that’s definitely the case in management consulting.
Top firms typically make offers to only about 1% of the people who apply. It’s not impossible to get a job with firms like McKinsey, Bain, and BCG (also known as the MBB firms), but it requires preparation.
In particular, successful candidates know that consulting firms use a particular type of interview question — the case study interview — and they know what recruiters are looking for in answers.
In this article, we’ll help you prepare for management consulting interviews by answering the following questions:
- What is a case interview?
- How do I answer a case question?
- What is the best approach for case interview prep?
We’ll also provide tips and tricks that will help you to ace your case.
Whether you’re aiming for a job at one of the MBB firms (McKinsey, Bain, or BCG), with other consultancies such as AT Kearney, L.E.K. or Oliver Wyman, or with the consulting arms of the large accounting firms such as Deloitte, Accenture, PwC, Ernst & Young, or KPMG, we can help you get there.
What Is a Consulting Case Study Interview (also known as the “Case Interview”)?
A Case Study Interview is a real-time problem-solving test used to screen candidates for their ability to succeed in consulting.
The case is presented as an open-ended question, often a problem that a specific type of business is facing, that an interviewer asks a candidate to solve.
Sample Case Interview Questions
Sales of drinks in Coffee Bean cafes are decreasing. What is causing the sales decrease?
Turnover of store employees at Burgers R’ Us restaurants has increased over prior years. What would you advise the company to do?
Donations to Caring Hands are decreasing, straining the non-profit’s ability to help the families it targets. What should the organization do to turn this around?
Why Do Top Consulting Firms Use Case Interview Questions?
Management consultancies are not the only types of firms that use case interview questions to evaluate candidates.
Investment banks, consumer marketing companies, and others use the case interview structure in their interview process.
Why?
Because case interviews show how a candidate would problem solve in real time.
Solving complex, ambiguous problems is at the heart at what consultants do every day.
This type of interview question mimics the analytic process a consultant might go through in a 3-month project, but it does it in 30 minutes, the time allowed in a typical interview.
The interviewer can probe whether a candidate’s approach is well-structured, creative, and displays good business sense.
How Do Consulting Recruiters Evaluate Candidates?
The main thing that recruiters are looking for in case study interviews is whether or not they’d feel comfortable putting a candidate in front of a client. To assess that, they ask themselves these questions:
- Is this person able to do the job? Do they have the analytic skills to solve tough business problems?
- Is this person client-ready? Are they knowledgeable, professional, and confident enough to work effectively with client staff and leaders?
- Is this someone I’d want to work with? This interview question is sometimes referred to as the airport test. It comes down to, “Would I want to be stuck in an airport with this person if the weather was bad and our flight was delayed?” It assesses whether an individual is smart, fun and passionate about the projects they take on.
- Is this person coachable? No one expects a recruit to know the answer to every thorny business issue right out of undergrad, or even right out of business school, but they do want someone who is willing and able to take suggestions and improve their analysis. Show you are coachable by listening for feedback as you answer a case study interview question and using suggestions to steer you toward the right solution.
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Consulting Case Prep Takes Time – So Start Early
If you walk into your first consulting interview without having practiced case study interviews beforehand, you’re in for a painful experience. Case questions can cover any industry and multiple different types of business problems, so you’re unlikely to get lucky and know the answer.
We suggest your start your consulting case prep a few weeks before your interview. Starting with more lead time is even better. This will allow you to watch/read through a few consulting cases to get a sense for what to expect (continue to our case videos below for one example!) It will also give you time to find a couple friends or classmates who are also applying to consulting firms. You can give each other mock case interviews and be even more prepared.
Learn How to Case Quickly by Mastering Each of the 4 Parts of the Case
When you’re starting your consulting interview prep, it’s important to remember that the “right answer” is not simply a conclusion, but the methodical, the well-structured process used to reach the conclusion.
To answer a case question correctly, you must:
Step 1: Understand the question you are being asked.
After your interviewer describes the client this case interview will involve and the problem they face, you should repeat this information back to them in your own words.
This can feel awkward when you practice your first case, but it will help you in the long run.
If you don’t have the client and their problem straight, you could spend a lot of time answering the wrong question. If that happens you will not be moving forward to second round interviews no matter how elegant your analysis is.
Example: Our client is a fast-food retailer that has seen decreasing sales revenue over the past couple of years. They want your help in understanding what they can do to improve sales.
Step 2: Take time to think through all the key aspects of the problem.
Ask for a moment to consider your approach to solving the client’s problem. During this time, write down what you want to learn about the client’s situation before you answer the interview question.
Your approach can lean on business frameworks you’re familiar with during your case interview preparation.
For instance, in the example of a fast-food chain with declining sales, you should break sales down into price and unit volume to understand whether the client is not selling enough units of their products or whether prices have fallen (or both!)
But you don’t need to use familiar frameworks. In fact, it’s best to develop your own structure for breaking down the problem as it shows you can solve a case without forcing a standard framework on the problem.
For more information on business frameworks, you might want to become familiar with during your case study preparation, see Case Interview Frameworks.
Step 3: Ask pertinent questions and use information from the interviewer to form hypotheses about the problem and explore potential options.
After you brainstorm key aspects of the case problem and structure your approach to solving it, share your approach with your interviewer.
If the interviewer suggests a place to start your analysis, follow their lead.
Otherwise, suggest the best place to start digging into the case.
Make sure the questions you ask the interviewer touch on all the key aspects of the problem you identified including the client’s internal organization, the market for their product, and their competition.
Step 4: Summarize your case interview conclusion in a persuasive manner.
Once you’re confident you have enough information to understand the case and what needs to be done to solve the client’s business problem, you’ll conclude the interview with a logical summary outlining the problem, key conclusions you’ve reached, and providing a persuasive recommendation on how you’d help the client resolve it.
Below, we’ll go into more depth on how to address each of these 4 points in a case.
Questions You Should Ask Yourself Before Diving Deeper into Case Interview Preparation
Right now, you may be thinking to yourself that consulting interviews sound impossibly difficult. Or you may think that they sound like interesting business problems that you’d enjoy solving.
Perhaps you’re not sure.
If you think that answering case interviews is not something that would come naturally to you, don’t worry, you’re not alone!
Getting good at consulting interviews requires a lot of preparation.
Before you commit to putting in the time required to prepare for the management consulting interview process, you should ask yourself if a career in management consulting is right for you.
Key Questions to Ask Yourself Before Pursuing a Career in Consulting
- Do you enjoy solving the types of business problems asked in case interviews?
- Do you have a background in business principles or are you willing to invest the time it will take to develop one?
- Are you passionate about pursuing consulting as a career?
Management consulting jobs might pay well and provide the opportunity to pursue attractive careers, but if you don’t like solving business problems, you probably won’t like the work you’ll do as a consultant. If you don’t enjoy analyzing business cases, save yourself a lot of preparation time and frustration.
Focus on career options that better meet your interests.
Or, perhaps solving business problems with smart, driven professionals sounds like it’s your dream job.
If so, move onto the deeper dive into case interview prep below!
Case Interview Prep – Diving Deeper
If you’re here, we’re assuming you’re serious about investing time in preparing for a career in management consulting.
The best way to get smarter about answering case interview questions is to master this four-part approach.
How to Answer a Consulting Case Interview – a 4 Part Approach to Practice During Interview Prep
The 4 parts to answering a consulting case interview are:
- Opening – This is where you make sure you understand the client’s problem.
- Structure – This is where you brainstorm all factors relevant to the problem and organize them to ensure you address them in a complete and logical manner.
- Analysis – This is where you gather data to identify which of the factors related to the business case are the most important. You’ll use this data to create a recommendation for your client.
- Conclusion – Here, you present your recommendation to “the client” (your interviewer), in a well-structured and persuasive manner.
Case Interview Prep Part 1: The Opening
As we saw in the video above, the opening of a case question is a description of a client and the problem they’re facing. Rebecca repeated back to the interviewer the type of business the client was in and and their business problem.
Remember, this clarification is an important step in the process.
If you did not remember that the client was a top-three beverage producer and answered the question as if the client was a start-up, your answer would ignore the manufacturing and distribution infrastructure the company already had in place to launch its new product.
That would make your answer completely wrong.
During this portion of the interview, you can ask any clarifying questions you need to. If something is not clear—the client’s product or industry, or the problem they want to solve —ask!
Nailing the opening is probably the easiest part of case interview preparation. Get this right, and you’ll start each case off strong.
Case Interview Prep Part 2: Structure
Once Rebecca clarified the problem, she asked for a moment to prepare her response. In the structure phase of the case interview, there’s silence for several moments.
As with clarifying the question, this can feel awkward.
But asking for this time will show the interviewer that you’re carefully structuring your problem-solving approach.
It will also ensure that you are not quickly addressing a couple of aspects of the business problem but ignoring others, potentially ones that are critical to solving the client’s problem.
Some quick brainstorming is useful here, but also take a step back to maker sure you consider all aspects of the client’s business, its customer demand, and the competition.
Organize your questions into a comprehensive approach to address all key aspects of the problem.
Mastering the structure phase of the interview is not as easy as the opening, but it’s critical to ensure you have the structured problem-solving approach that will lead you to the right answer to the case.
Focus on this aspect of case interview preparation until you can structure almost every case right.
Case Interview Prep Part 3: Analysis
In the third part of the case study interview, you’ll dig in and analyze the problem.
After Rebecca outlined her problem-solving approach, the interviewer told her that the client wanted to understand the beverage market and customer preferences to assess the potential success of the product launch.
The interviewer then provided a chart with helpful data.
This part of the interview is important because gives you the data that will help you close down aspects of the case that aren’t at the heart of the problem you need to solve and to better understand key drivers that will point to the solution.
But you’ll also need to do some consulting math.
You can ask relevant questions that will give you data on each aspect of the problem you identified in the structure section.
You should provide insights into the case based on the data you receive and should use your insights to dive deeper into relevant aspects of the client’s business.
You should also refer back to the problem-solving structure you laid-out earlier in the interview to make sure your analysis is comprehensive. You don’t want to get lost down one rabbit hole and ignore other important aspects of the problem.
During this portion of the interview, you’ll be assessed on whether you asked relevant questions, have well-reasoned insights into the client problem, and whether you could lead a case like this if you were hired by the firm.
Many consulting candidates find that the analysis phase of the interview is the toughest of the 4 parts.
You need to balance doing consulting math calculations with interpreting data and make sure you cover all aspects of the problem you identified in the structure phase of the case.
Stick with this aspect of case interview preparation until you’re an expert at it–it will pay off in your interviews.
Case Interview Prep Part 4: Conclusion
Rebecca concluded the case with a direct answer to the case study interview question as it was initially asked.
This answer should be both persuasive and logical based on all the information gathered over the course of the interview. Your answer should also include the next steps your client should undertake.
During the conclusion, you’ll be assessed on whether you present a well thought-out solution based on the relevant facts of the case.
Like the opening, mastering the conclusion is not difficult. Take you time to nail this aspect of case interview preparation anyway as leaving your interviewer with a strong impression of your casing capabilities is important.
The Bottom Line for Effective Case Interview Prep
The case study interview is not as complex as it seems if you break it into 4 parts.
Practicing each part of the case on its own will make your consulting interview preparation both more efficient and more effective.
Now that you’re familiar with the 4-part approach to a case interview, the next thing to learn is the 4 different formats case interviews can take.
4 Formats for Case Interviews
There are four formats a consulting case interview can take:
- Candidate-led – This is the most typical case study interview format. A candidate is given an open-ended business problem to solve by an interviewer. The candidate will break down the question into key parts and decide which part to probe first. The interviewer is looking to see that you know how to drive the analysis of a problem. This case format is typically used at firms like Bain, BCG and Oliver Wyman.
- Interviewer-led – In this case interview format, a candidate will still be expected to identify and structure the key elements of a thorny business issue, and then present them to the interviewer. But after they do, the interviewer will direct them to first address a particular aspect of the case. This interview format is typically used in McKinsey cases.
- Written interview – This is not a common interview format but can be common for particular companies and offices. You will be given a packet of PowerPoint slides and time to review them. During this time, you’ll prepare a presentation using the slides you choose from the ones provided as well as others you create, and you’ll then present it to a panel of interviewers. Written interviews are frequently used by boutique consulting firms and regional offices of larger firms such as Bain’s China offices. For more information, see this article on written case interview.
- Group interview – Multiple candidates are brought in to discuss a case together and then present their solution to an interviewer. The group case is also not a frequently used interview format. For more information, see this article on group case interview.
While the candidate-led consulting interview is the most frequently used format, you’ll probably see more of the interview-led interview format in McKinsey interviews.
You should also be aware of the written and group interview formats so that if you get one during the interview process, you’re not caught by surprise. But don’t spend a lot of time on preparation for that type of interview unless you’re informed you’ll have one.
Congratulations!
You’ve made it to the end of our crash course on case interview prep. By reading this article, you now have a strong understanding of:
- What a consulting case interview is,
- How to answer case studies using the 4-part approach, and
- What the 4 different formats for case interviews are.
You are well on your way toward preparing for your first case interview and entering the exciting field of management consulting.
Still have questions?
If you still have questions on case interview prep, leave them in the comments below. We’ll ask our My Consulting Offer coaches and get back to you with answers.
Also, we have tons of other resources to ensure you get an offer from a top management consulting firm. Check out these topics:
Help with Case Prep
Thanks for turning to My Consulting Offer for advice on case interview prep. My Consulting Offer has helped almost 85% of the people we’ve worked with get a job in management consulting. For example, here is how Brenda was able to get a BCG offer when she only had 1 week to prepare…
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2 thoughts on “A Comprehensive Guide to Case Interview Prep [updated 2021]”
In the math calculations of the analysis portion, why was it that there were 8 cans per gallon? Where did that number come from?
Hey, Tonia! Thanks for your question.
In the case, we’re given that the size of the market for US sports drinks is 8 billion gallons. Electrolyte drinks are 5% of this total or .4 billion gallons which equals 400 million gallons.
We’re also given that the product size for drinks in this market are 16 ounces. And in our breakeven analysis, we find out we need to sell 400 million bottles (or cans) to break even. We need to do a conversion to compare our breakeven point of 400 million bottles to the 400 million gallon market size to see what market share we would have to achieve to break even.
Conversion: 1 US gallon = 128 ounces. 128 ounces/ gallon divided by 16 ounces/ bottle = 8. We can fill 8 bottles for each gallon of electrolyte drink we produce. So 1 gallon is 8 bottles (or cans) manufactured by our client.
We divide the 400 million bottle (or can) breakeven point by 8 to get to 50 million gallons. We compare the 50 million gallon breakeven point to the 400 million gallon market size to see that we need to capture 12.5% market share.
Note: In answering this question, I noticed that a UK gallon = 160 ounces, so if you are using UK gallons you will get a different answer!
I hope that helps! Sorry about the confusion between US ounces/gallon and UK ounces/gallon!