A Comprehensive Guide to Case Interview Prep [tips updated 2022]

Consulting informational interview. this image shows two women discussing a business problem in an office.
Rebecca Smith-Allen
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

Case Interview Prep

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”)?

Example-Case-Interview-Questions-3-768x432 (1)

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?

Case Interview 101 – The Basics for Beginners

You don’t need an MBA or an undergraduate degree in economics to land a job in consulting. But you will need to learn some business basics to be able to crack case interviews.

This section covers the concepts non-business students need to become familiar with, such as:

  • The income statement – an overview
  • Common formulas used in case interviews
  • Business concepts you need to know
  • Common types of case interviews

Case Interview 101, Part 1: The Income Statement

To solve cases, you first need to understand broadly how companies make money. For any specific case, you’ll want to make sure you understand how that company makes money. 

The most common way companies make money is by selling a product or service for more than it costs to produce, thereby earning a profit

Companies use three major financial statements to monitor and report their financial performance: 

(1) The income statement
(2) The balance sheet
(3) The cash flow statement 

An income statement (or profit and loss statement or statement of revenue and expenses) is a record of a company’s profit or loss over a specific period of time. The profit or loss is calculated by taking the revenues generated and subtracting the expenses incurred over the same period of time. The income statement has 3 major categories: Revenue, Expenses, and Profit or Loss.

Revenue:

Revenue is the total amount of money generated by a company from selling its products or services. It is also referred to as gross sales or “top line” as it sits at the top of the income statement. 

Costs:

Costs are expenses incurred by a company to make its products or services. In the income statement there are three types of costs: 

  • Costs of goods sold (COGS) or cost of sales are the direct costs of making products or providing a service. For a burger restaurant, for example, the COGS would include things like the meat, bun, and hourly labor of cooks, cashiers, and shift supervisors.
  • Operating expenses are costs that are indirectly tied to the making of products or services. These include selling, general and administrative (SGA) expenses, management salaries, depreciation and amortization. Depreciation and amortization are non-cash expenses that reflect the value of big assets like machinery or buildings going down over time. For example, if our burger restaurant buys a grill to cook burgers on for $1,000 and expects it to last for 10 years, it would spread out the cost over that time period, $100 per year. Other operating expenses for our burger restaurant would include things like advertising, the rent on the company’s headquarters, and the salary of the CEO.
  • Costs incurred from non-operating activities such as interests paid on loans. These costs are rarely part of case interviews.

Profit or Loss:

Income statements generally show 3 levels of profit (loss) or earnings: Gross Profit; Earnings Before Interest, Tax, Depreciation and Amortization (EBITDA); and Net Profit.

Gross profit or loss

This is calculated by subtracting COGS or the cost of sales from the total revenue generated. If the costs are higher than the revenue generated, then the company has made a loss.

EBITDA and EBIT

EBITDA is calculated by subtracting operating expenses from the gross profit. EBIT is calculated by subtracting depreciation and amortization from EBITDA. 

As mentioned above, depreciation and amortization are non-cash expenses. So if the amount of cash generated by selling a product or service is important to your analysis, you should look at EBITDA. If looking at a more fully-loaded cost is the focus of your analysis, use EBIT.

Net Profit or Loss

This is calculated by subtracting interest and tax from EBIT. It is also known as Net Income and refers to the profit (or loss) for the period. This is also known as the “bottom line” as it sits at the bottom of the income statement. This is the ultimate measure of whether a company’s activities are profitable during a certain time period when all costs are considered.  

Case Interview 101, Part 2: Common Formulas Used in Case Interviews

Here is a look at common formulas used in case interviews.

Profitability formula:

The profitability formula is used in profit (or loss) related cases. The profit or loss can be calculated using the following formula:

             Profit (or Loss) = Revenue – Costs

As mentioned above:

  • Revenue is the money generated from selling a product or service. It can be broken down into price per unit and number of units sold
  • Costs are the expenses incurred to make the product or service and can be broken down into cost per unit and number of units sold

The formula can further be broken down into:

            Profit (or Loss) = (price per unit x number of units sold) – (cost per unit x number of units sold)

There are other ways to break down revenue and cost depending on the case question.

  • Revenue can be broken down by product or service line, customer type, or geographic region (e.g., North American, Europe, Asia)
  • Costs can be broken into fixed costs and variable costs, or components such as overhead, salary, etc.

It is often helpful to break costs down into fixed and variable to solve consulting cases, and understanding the difference is important. Fixed costs, like rent for a store or the cost of equipment, are incurred regardless of how many units a company sells; whereas variable costs are only incurred with the production of each additional unit. Because of this, it can be helpful to sell incremental units even at a loss for a short period of time if it helps cover fixed costs.

So the profitability formula can also be written as:

            Profit (or Loss) = (price per unit x number of units sold) – (fixed + variable costs)

Profitability example:

Your client, a manufacturer, is facing a decline in profits. Your client wants your help solving this problem. We’ll use this example to demonstrate all the formulas in this section.

The first step you could take is to calculate the past year’s profit given the following information:

  • Number of units sold = 1 million
  • Price per unit = $10
  • Cost per unit = $8

          Profit (or Loss) = ($10 x 1 million) – ($8 x 1 million)

          Profit = $2 million

Profit margin formula:

Profit margin indicates how many cents of profit the company generated for each dollar of sale. It’s typically used to measure the financial health of a company. You can compare the profit margin of a company against its historical margins to evaluate whether its current performance is better or worse than past performance. You can also compare it against companies in the same industry to evaluate whether its financial performance is stronger or weaker.

Profit margin can be calculated using the formula:

          Profit margin = (Profit / Revenue ) *100%

Profit margin example:

To calculate the profit margin, first, you need to calculate company revenues as follows:

           Revenue = 1 million x $10

           Revenue = $ 10 million

You can now calculate the profit margin as follows:

           Profit margin = ($2 million / $10 million) x 100%

           Profit margin = 20%

Note you can combine both the formulas for faster calculation.

Market share formula:

Market share is the size of the company in relation to the size of the industry in which it operates, where size is typically measured in annual revenues. It is used to compare the size of a company to its competitors and the industry as a whole. It can be used in market entry cases because industries with a lot of small competitors are generally easier to enter than ones with only a few big competitors. It’s also used in profitability cases because, in general, companies with a large market share also have more market power to do things like set prices.

Market share can be calculated using the following formula:

            Market share (%) =total company revenue / total industry revenue  

Market share example:

Using the example from above, say you decide to determine the company’s market share as part of your analysis. In this example, the industry has annual revenues of $ 200 million.

            Market share (%) = $ 10 million / $ 200 million

           Market share = 5%

Growth Rate Formula:

This refers to the specific change of a variable within a specific period of time. Growth rates can be used in assessing the financial performance of a company over time. For example, high revenue growth rates would likely be a sign of strong financial performance. High cost growth rates may be a sign that a company is having financial trouble.

The growth rate is calculated using the formula:

            Growth rate (%) = (New – Old) / Old

Growth rate example:

To calculate the manufacturer’s revenue growth rate. Last year’s revenue was $ 9.5 million therefore the revenue growth rate is:

            Revenue growth rate = ($10 million – $9.5 million) / $9.5 million

            Revenue growth rate =5%

You can assess whether a company’s growth rate is strong by comparing it to other growth rates such as:

  • The company’s growth in the prior year.
  • The growth of the market or of competitors.
  • The rate of inflation.

Mature companies are likely to see single-digit growth rates unless they launch a very successful new product or they acquire a company. On the other hand, startup investors typically expect double- or triple-digit annual growth during a company’s early years.

Return on investment formula:

Return on investment (ROI) is a profitability metric that indicates how well an investment performed (or will perform). It can be used to compare the profitability or efficiency of an investment or decide which of alternative investments to make. 

ROI is calculated using the following formula:

            ROI (%) = Profit / Cost of investment

ROI example:

Suppose our manufacturer mentions that they purchased state-of-the-art machinery to make their product. It cost $8 million. You decide to calculate the ROI on this investment. 

            ROI  = $2 million / $8 million

           ROI=25%

Break-even formula:

Break-even is the point at which the total revenue and total costs are equal, meaning there is no loss or profit at that point. Break-even is typically used to help companies determine the minimum number of units that need to be sold to cover all the costs used to produce those units. 

An executive might want to know that they could break even at 100,000 units sold because if she thought they could sell more than that, it would be profitable to enter the market. If she thought they’d sell less, they wouldn’t enter the market.

Break-even can be calculated using the following formula:

             Breakeven (units) = Fixed costs  / (sales price – variable cost per unit)

Break-even example:

If a product required a $50,000 investment in equipment (a fixed cost), sold for $5, and cost $4 per unit in variable costs, its breakeven would be: 

              Breakeven (units) = $50,000  / ($5 – $4)

              Breakeven= 50,000 units

Payback period formula:

Managers may also look at the payback period on an investment or, in other words, how long it would take to earn back the cash required to enter a new business. This investment could be a new piece of equipment or a marketing campaign needed to create customer awareness of a new product. This is a different way of looking at the same question that the breakeven formula asks: is it worth my while to make this investment?

The payback period can be calculated using the following formula:

             Payback (years) = Investment cost / annual profit

Payback years example:

Using the same example, you decided to calculate the payback years of the new state-of-art machinery

           Payback (years)= $8 million / $2 million

           Payback = 4 years

Capacity of equipment:

The capacity of equipment is the maximum output or units a piece of equipment can produce with the available resources over a set period of time.

Capacity can be calculated using the following formula:

            Capacity (units) =Total capacity / Capacity required to make one unit

Capacity example:

To calculate the capacity of our manufacturer’s machinery, we’d need to know that it can produce a unit every 10 minutes and that the client operates 12-hour shifts.

             Capacity (units) = 12 hours x (60 minutes per hour) / 10 minutes

             Capacity = 72 units / day

The utilization rate of equipment:

Utilization rate is the percent of available time the equipment or machinery is actually used. It measures efficiency and can be used by companies to make informed decisions on timelines and inventory, or whether additional equipment is needed.

The utilization rate of equipment can be calculated by the following formula:

              Utilization rate (%) =Actual output / Maximum output

Utilization rate example:

Using the same example, imagine that the management tells you that in a 12-hour shift, the machine produces 50 units and there are two 45-minute breaks.

First, you would need to calculate the potential output.

               Actual hours of operation = 12 hours – 1.5 hours = 10.5 hours

               Potential output = (10.5 hours / 12 hours) x 72 units

               Potential output = 63 units

Then, calculate the utilization rate.

                Utilization rate = 50 units / 63 units

                Utilization rate = 79%

Utilization rates raise interesting issues in a case. It raises questions such as:

  • If potential output is 63 units, why are only 50 being produced (e.g., machine downtime, worker errors), and what can be done to solve these problems?
  • Could the company stagger employee breaks to get potential output up to 72 units from 63?

Case Interview 101, Part 3: Business Concepts You Need to Know

Here are some common business concepts that you need to know as you prepare for your interview.

Process: This is a set of actions or operations that lead to results (products or services). This typically describes how a company makes its products or services. The steps can be performed by workers, equipment, or computers. In a case, this is mostly used in situations where a client would like to make their processes more efficient. For example, a client who is in logistics would like to reduce the cost of its operations by improving the efficiency of its processes, such as by reducing equipment downtime or scheduling deliveries according to time-saving routes. 

Best practices: Best practices are methods or techniques that are considered to be the working standards and guides in a given situation. In a business situation, best practices are used to benchmark companies against the standard and can serve as a roadmap on how to improve the efficiency of their operations.

Hypotheses: Tentative answers to a problem or an assumption based on some evidence. The hypothesis-driven approach is a common approach to solving problems in the consulting world because consultants don’t want to waste time fully researching all possible solutions. They want to move quickly to the most likely answer and then test whether it is or is not the best answer. This approach can be used to solve case interview questions where you first assume an answer to the case problem and check whether this is true or not through analysis. If it is not true, you revise your hypothesis.

Issue tree: This is a common approach in consulting used to solve complex problems. An issue tree is used to break down complex problems into key components in a structured manner. In a case interview, you can use the issue tree to break down the client’s problem into manageable chunks or to break down a formula such as the profitability formula into key components.

Read our article for more information on Issue Trees.

MECE: MECE stands for mutually exclusive and collectively exhaustive. It is a way of bucketing problems, ideas, or solutions with no overlapping between the buckets and with each item having a place in one bucket only (mutually exclusive), and with the buckets including all possible items relevant to the context (collectively exhaustive). In a case interview, you can use MECE with the issue tree when breaking down problems or when identifying solutions for the client. MECE issue trees are considered the gold standard for problem-solving so this concept is very good to know. 

You can also use the concept of MECE when segmenting a market – for example, if you are sizing a market and intend to lay out different purchasing behavior assumptions for different customer segments. For example:

Customer segment                       Purchase frequency for items from coffee shops

Women under 30                            4 times per week, purchase includes food item plus beverage
Men under 30                                   2 times per week, purchase includes only beverage
Women 31 and over                        4 times per month, purchase includes only beverage
Men 31 and over                               3 times per month, purchase includes only beverage

Note how in this example, everyone would fall into one customer segment and only one customer segment. Read our article for more about MECE problem-solving.

Root causes: This is the core issue or main reason for a problem. It is used in problem-solving to identify solutions that appropriately address the problem. The term root cause is used to distinguish between symptoms of a problem, which may be obvious, and the underlying issue that needs to be solved, which may not be obvious. For example, a decline in sales volume is a symptom. The root cause could be high prices, poor product quality, product unavailability, or any number of other issues. You can’t fix the symptom of declining sales volume until you identify the root cause behind the problem. 

In a case interview, you’ll need to identify possible causes of the client’s problem and then ask questions and do analysis to identify the root cause. Once you do, you can make the most appropriate recommendations for the client.

Break-even analysis: This is the calculation used to determine the point at which the total revenue and total costs are equal meaning there is no loss or profit. In business situations, it helps determine at which point the business, investment, or new product or service will become profitable. In case interviews, you can use the break-even analysis to determine whether a client should make a certain investment, say in machinery or a new product line, based on how likely it is that they’ll exceed the break-even threshold.

Case Interview 101, Part 4: Common Types of Case Interviews

In this section, we will review 4 common types of case interviews.

Market-sizing Questions

Market-sizing questions typically appear in cases where clients want to grow or expand their business such as market entry or profitability cases. The client either wants to understand the market size of the current business or of a potential new product line or geography or customer group to understand whether it is big enough to be interesting. 

Sample case questions

“How many cups of coffee does Starbucks sell in a day?”
“Estimate the fleet size of Delta Airlines.”
“Estimate market size for air-conditioners in New York.” 
“Estimate market size for an anti-smoking pill in the U.S.”

You are not expected to know the exact answer to market-sizing questions. Instead, the interviewer wants to see that you can use simple math and logical deduction to build out an answer. For these questions, it is good to memorize a few facts that will help you make assumptions. For example, a good place to start is the population of the U.S. or the population of a U.S. city (or country and city that you live in). 

For more information and examples, read our article on Market-sizing Cases.

Revenue Growth Case Interviews

In revenue growth cases, the client typically wants to grow their business. This can be done by increasing revenue of the current product/service line, by adding a new product/service line, or by selling to a new type of customer or in a new geography. 

They could do this by building a new offering, buying another company, or partnering (joint venture) with another company that already offers what they want to sell. 

Sample case questions

“A manufacturer sees its revenue stagnating. It wants to know whether raising price or selling more units is a better path to growing revenue, and how to pursue it.”

“A local theater house thinks there is an opportunity to expand their current offerings to the very loyal client base. What new product or service could they offer their customers? What would be the impact on revenue from expanding their offerings?”

“A regional fast-food chain, serving hamburgers and fries, is experiencing increasing demand outside of its main regions of operation and wants to expand. What regions would have the biggest impact on its revenue?”

You should remember that there are multiple ways to achieve revenue growth. One thing to consider is the client and industry context when tackling revenue growth questions. For example, does the client have a good market size in the industry? Does the client have the capability to offer new products/services? Is the industry highly competitive?

For more information, read our article on Revenue Growth Cases.

Market Entry Case Interviews

In market entry cases, the client wants to know if they can enter a market and be profitable. For example, entering a different geography, new demography, or new product/service line. (Note, there can be overlap between revenue growth cases and market entry cases.)

Sample case questions

“A U.S.-based consumer electronics manufacturer is thinking of expanding into emerging markets. What is the potential revenue growth if they choose to expand into India?”

“A telecom operator is looking to diversify their presence in the U.S. and wants to enter the video streaming market. How can they capture a significant market share?”

“A renewable energy company that specializes in large equipment such as windmills wants to enter the retail market and sell smaller equipment directly to individual homes. They would like to know if this is a good idea.”

There are a number of frameworks you can build off of to tackle a market-entry case. For example, Porter’s Five Forces, Business Situation Framework or 3C&P (customer, competition, company, and product), and Supply & Demand among others. It is key to consider the “new” market context as well as the client context to enter this market. 

To find out more on this, read our article on The Market Entry Framework.

Cost Optimization Case Interviews

Cost optimization cases or questions can be part of a profitability case where a client is experiencing declining profitability or when a client wants to improve efficiency.

Sample case questions

“A national hotel chain has seen its operational costs significantly increase over the last year and would like you to figure out why.”

“A juice manufacturer has been experiencing a steady increase in revenue over the past 5 years however their cost has been increasing at a faster rate, meaning the profits have not grown as expected. What is the root cause of the significant increase in cost?”

“A tour company would like to reduce their costs due to the falling number of tourists over the past few years. What ways would you recommend for them to reduce their costs?’

For cost optimization cases, remember to break down the cost components. For example, you can break them down into fixed and variable costs or cost of goods sold and operational costs and then brainstorm the categories of each that will likely apply to the company at hand. This will make it easier to identify what costs should be reduced or eliminated.

Check out Types of Case Interviews article for more detail on these types of cases and more.

Why Do Top Consulting Firms Use Case Interview Questions?

Case Interview Prep

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:

 

How to Answer a Case Interview

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

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

Case Interview Preparation

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:

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6 thoughts on “A Comprehensive Guide to Case Interview Prep [updated 2022]”

  1. In the math calculations of the analysis portion, why was it that there were 8 cans per gallon? Where did that number come from?

    Reply
    • 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!

      Reply
  2. Hi, what resources are you typically allowed to use during (virtual) case interviews? Such as a pen, paper, calculator etc.

    Reply
    • Hey, Ella!

      You’re typically allowed a pen and paper in a virtual case interview but NOT a calculator. Part of what your interviewer is testing for is your quantitative skills, so they want to see that you can do calculations in your head or on paper. See our article on virtual case interviews, for more info. Also, we have an article on practicing your case interview math.

      Best of luck!

      Reply
  3. Hi,

    Can you please explain the ROI formula? I do not understand why (2m-8m)/8m = 25%. That calculation gets a result of -75%

    Shouldn’t the formula just be (net profit)/(cost of investment)?

    thanks!

    Reply
    • George, thanks for pointing this out! The formula was incorrect, and should be Profit/cost of investment. The correct answer is 25%.

      All the best,
      MCO

      Reply

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