Case Interview Guidelines – for Consulting Interviews

Introduction to the Case Interview

Case interviews are often used by employers as part of the screening process for new hires. They are nearly ubiquitous in the consulting industry, and other industries have also begun to adopt them to evaluate talent. 

Case problems presented in these interviews are often representative of larger, more complex business problems. Consulting and finance firms often use case interviews as a method to gain insight into the way you think, solve problems, deal with uncertainty, and present solutions. In addition, cases are also used to gauge your presentation skills, client management skills, how you collaborate, and how you respond to critique. The bottom line is: cases provide a window into how you communicate and collaborate.

There is no single “right” approach to answering the problems interviewers present. That being said, there are frameworks and principles that you can use to structure your response, think critically about potential solutions, and respond to follow-up questions.

Frameworks are quite helpful, but it’s easy to get hung up on selecting which one to use. What is more important than selecting a specific framework is capturing all the small parts of a solution in a simple, elegant way. One very effective approach to this is MECE (me-see), which stands for Mutually Exclusive and Collectively Exhaustive. This means when you are giving your answer, all of the information should be grouped into categories where there is no overlap between categories (mutually exclusive). In addition, all of the categories added together cover all possible options (collectively exhaustive). You’ll want your solutions to be MECE. Here are two examples:

  1. For a case that asks you to maximize profits

Wrong approach: “All we have to do is increase revenues.” This is tempting because revenue is related to profit, but it is not the full picture.

Right approach: “We have to examine ways to increase revenue and/or decrease expenses.”

Why: Profit = Revenue – Expenses. To fully analyze this case, you need to explore all parts of this equation.

  1. For a case about categorizing customers of a pizza restaurant into different segments

  Wrong approach: Let’s look at delivery customers and college students

Right approach: Can we assume this scenario takes place before COVID-19? Yes? In that case, let’s divide the restaurant clientele into three types of customers: dine-in customers, take-out customers, and delivery customers

Why: The first approach isn’t mutually exclusive because it’s possible for a customer to be both a delivery customer and a college student. It also isn’t collectively exhaustive since it leaves out some types of customers such as dine-in high school students. The second approach manages to slot every possible type of patron into exactly one category without any exclusion or overlap. This method is also strong because it shows an awareness of current events. 

Set Yourself Up for Success

Case interviews are just as much about showing employers your thought process and communication skills as they are about getting the right answer. It is important to listen well, ask questions, and check in with your interviewer to make sure that you are on the right track.

Here are some guidelines:

  • Take notes throughout the exercise
  • Restate the question to ensure that you are solving the correct problem
  • Listen for keywords. For example, “evaluate” indicates the interviewer wants to hear pros and cons, whereas “committed” means your answer will be focused on “how” to accomplish a goal.
  • Treat the interaction with your interviewer as a conversation. Interviewers will do what they can to help you; they are not there to trick you.
  • Show and communicate your work as you go through the exercise. This includes both walking through how you arrived at conceptual conclusions, as well as demonstrating any necessary math. Always tell the interviewer why you are taking a specific direction.
  • When possible, state some assumptions that allow you to frame an answer where you can’t be wrong. (e.g. “For the purpose of addressing this problem, I am going to set the population at X.”) After stating this, pause to enable your interviewer to weigh in if you are going off course.
  • Interviewers are looking for structured thinking. This means you should categorize different parts of the problem whenever possible, and you should sequence your steps in a logical order. 
  • Explain how you arrived at your answer so that the interviewer understands your thought process. This includes explaining lines of thought you ultimately rejected.
  • At the end, always give a concrete recommendation, propose any barriers or risks to your recommendation, and state what you have learned in this interview.

Sources of Information

Over the course of the interview, you will gain more information about the specifics of the case. It is important to consider all available information.

  1. What you know inherently: You will likely have a bit of background knowledge on the topic. State it so the interviewer knows where you are coming from, and think about how you can incorporate it into your answers.
  2. What you have been told by the interviewer: Initially you will only be given the broad strokes of the problem. From this you need to develop a big-picture plan before diving into the specifics.
  3. What you don’t know but need to know: Don’t hesitate to ask pointed clarifying questions to gain vital information. Many case interviews are structured to roll out new information in stages. Asking the right questions can yield information critical to solving the overall problem. When you ask for new information, make sure you explain why you need this information.

How to Get Comfortable with the Case Interview Process

Here are a number of resources you can use to prepare for Case Interviews:

Employer-Developed Case Preparation Tools

Other Valuable Resources

Once you’ve developed an understanding of the process, it’s important to practice case interviews. You can practice with friends, classmates, and mentors. Find time to practice cases together, either 1:1 or in groups.

You can also log into CPD’s Handshake platform to sign up for an appointment to do a mock case interview with a CPD Coach. Each coach has a collection of cases – and can run through one of them with you.