Case interview frameworks: how to structure a case in 2021

the image is the cover of an article on how to create a structure and framework in a case interview with mckinsey, bcg, and bain

Structuring your approach is the first step in every case interview. Initially, the interviewer will tell you about the client’s situation and the problem they are asking you to solve. After playing back the prompt and asking clarification questions, you need to structure your approach and create a case interview framework.

Getting the framework right is the first step to successfully ace the case. As with most other aspects of the case interview, it is a skill that needs to be learned, internalized, and practiced to perform best during the interviews. Hence, make it a priority in your case interview prep!

We want to give you a head start by answering the following questions in this article:

  • What is a case interview framework?
  • Why do you need to structure your approach?
  • Are there different types of frameworks?
  • What makes a good case interview structure?
  • Should you learn case interview frameworks by heart?
  • How do you structure a McKinsey case interview? Is it different from candidate-led interviews?

This article is part of our consulting case interview series. For the other articles, please click below:

What is a framework in a case interview?

A case interview structure is used to break the problem you are trying to solve for the client down into smaller problems or components. It is the roadmap you establish at the beginning of the interview that will guide your problem-solving approach throughout the case.

A structure usually consists of a top-layer and several sub-levels.

To illustrate, the most common and basic structure you might find in some preparation cases is:

Profit = Revenue – Cost

This high-level structure is used for profitability cases when you are tasked to solve an issue with the client’s profit development. For instance, ”client profit has gone down over the last year and we are not sure why that is the case.”

The structure above represents the top-level. In order to analyze the problem, you would need to go deeper and figure out what sub-levels influence the variables you are looking at.

It is important to tailor the structure and associated sub-levels to the case questions. Framework templates were en vogue 5-10 years ago and consulting firms have moved away from asking generic cases that would fit the frameworks taught by Case in Point or Victor Cheng (more on that below).

In terms of format, the best-practice approach to structuring a case is to build an issue tree with branches, which are split into several sub-branches. To stick with our example from above, check out our profitability framework below.

the image shows how to create a profitability framework in a case interview

Why do you need to structure your approach?

The initial structure you need to come up with serves three important purposes in a case interview.

Roadmap

First, it is the roadmap you establish initially that guides your problem-solving throughout the case. Once you layout your planned approach, you should go through each bucket or branch of your issue tree to find the issue(s) the client is facing or to evaluate the ideas you came up with to fit the needs of the client and then work on your recommendation(s). It serves as the anchor you should stick to as you move through your analysis.

Communication device

Second, it is used as a communication device to guide the interviewer through your thought process and approach. Additionally, moving through the structure allows you to ask targeted questions to the interviewer about additional data or information on each point.

Analytical test

Third, coming up with a proper structure (more on that below) and communicating it well is a test in itself. The interviewer tries to understand how well you are able to tackle unfamiliar problems. They will evaluate your thinking, logic, analytical capabilities, and problem-solving prowess as well as communication skills.

Are there different types of frameworks?

Generally, there are two types of structures that depend on the nature of the question.

Either you are asked to break a problem down into its parts and understand where an issue comes from to provide a recommendation (e.g. ”How would you approach…?”) or you are asked to come up with concrete ideas to make something happen (”What initiatives can you think of to…?”).

Figuring out a problem

A structure here is the starting point and anchor of your problem diagnostic.

First, you need to think about all potential problem areas, then drill down into each branch to figure out what is wrong exactly by collecting more information from the interviewer and exhibits; then provide a recommendation in the end.

Coming up with an approach

For these types of questions, a structure is a systematic collection of ideas that you want to investigate on behalf of the client to help them with a specific goal.

For both types of structures, you should follow a hypothesis-driven approach, i.e. already having a clear vision where the problem could be buried most likely or what approach or idea would best support the client’s goal.

Apart from that, what other characteristics make a good case interview structure?

What makes a good case interview structure?

A good case interview structure follows several rules. Let’s break them down into content and principles.

Content of good case interview frameworks

An excellent structure is broad at the top level, goes into greater depth on the sub-levels, and consists of meaningful and insightful ideas.

  • Breadth: How many buckets does your structure consist of at the top-level? While in a profitability case, the top-level is basically given, for many other cases you can expand your top-level to 6-8 buckets (Real MBB case question: ”What could be the reason our machines break down at different rates in different locations?”).
  • Depth: How deep do you go into each top-level idea and come up with levers below? How well can you support your top-level with the actual ideas that influence it?
  • Innovation: How meaningful and insightful are your ideas? Create a mix of common ideas and components as well as more out-of-the-box answers. Tell the interviewer something they have not heard before.

Principles of good case interview frameworks

Make sure that your structure adheres to the principles below.

  • MECE-ness: Refers to a grouping principle for separating a set of ideas into subsets that are mutually exclusive (no overlaps between the different branches of the issue tree) and collectively exhaustive (covering all important aspects). It is used to break down problems into logical and clean buckets of analysis.
  • Actionable: Your answer should only consist of ideas that you can actually exert influence on within the given time frame (e.g. if you are asked to come up with measures over the next year, everything beyond that should no be touched in your structure).
  • Logically coherent: Top-levels and sub-levels should be consistent within their level and across levels. They should stick to the same hierarchy of importance and logic (e.g. if you are comparing revenue and cost, they should be at the same level, and everything that influences the two should be below).
  • Relevant: The content should be relevant for the case at hand, tailored to the client, easy to follow and communicate. Avoid over-structuring your case.
  • Hypothesis-driven: You should have a clear idea of where the problem is buried or what solution is best for the client from the start, and while moving through the structure and gathering additional information, that hypothesis should become clearer.

Below is an example of a framework for the question we highlighted above.

”What could be the reason our machines break down at different rates in different locations?”

the image shows an example of a mckinsey case interview framework

This is just an example framework that covers many important aspects and adheres to the content ideas and principles we discussed above. By no means is this the only way to draft a structure here!

Should you learn case interview frameworks by heart?

Be aware that framework templates were applicable 10 years ago, the era of Victor Cheng and Case in Point. McKinsey and other top-tier firms have long caught up on this and the cases you will get during the interviews are tailored in a way to test your creativity and ability to generate insights, not remember specific frameworks.

In fact, it will hurt you when you try to use a framework on a case that calls for a completely different approach. Also, it gives a false sense of security that will translate to stress once you figure out how your approach won’t work during the real interview – We have seen this so many times…

Your goal should be to learn how to build custom issue trees and frameworks, interpret charts, and perform math no matter the context, industry, or function of the case. Our approach teaches you this and trains your ability to come up with deep, broad, and insightful structures for each case individually.

Now, if you come from a non-business background, it certainly does not hurt to glance over the classic frameworks once (e.g., market-entry, product development) to become familiar with the terms and phrases as long as you are aware that their usefulness ends there.

Also be aware that there is no typical McKinsey case interview framework, BCG case interview framework, or Bain case interview framework. All firms use a diverse set of cases, which are usually developed by each interviewer individually based on a real consulting project they have completed. If you are looking for case interview examples, check out this article, where we have compiled a link list of all publicly available MBB and tier-2 consultancy cases.

How to create a structure in a McKinsey case interview

Since the McKinsey interview is interviewer-led, there is extra emphasis on the structure.

At the core, McKinsey wants to see creative ideas communicated in a structured manner, the more exhaustive the better. Your goal should be to come up with a tailored and creative answer that fits the question.

In a McKinsey interview, you can take up to 2 minutes to draft your structure, IF the structure you come up with is strong and

  • hits all the key points that the firm wants to see and
  • is communicated in the right way.

A big issue I see with coaching candidates is that they take too little time to structure their thoughts because they feel pressured to be quick rather than exhaustive and creative.

An additional 30 seconds can often make the difference between a bad structure and a good one or a good one and an excellent one. So my battle-tested advice is to get rid of this time pressure mindset, especially in a McKinsey interview.

Now for the content of the structure, there is no right or wrong answer. Some answers are better than others because they are

  • deep
  • broad
  • insightful
  • hypothesis-driven
  • follow a strong communication (MECE, top-down, signposted)

That being said, there is no 100% that you can reach or the one-and-only solution/ answer. It is important that your answers display the characteristics specified above and supported well with arguments.

Also different from other firms, you can take up to roughly 5-6 minutes to present your structure, your qualification, and hypotheses. This is due to the interviewer-led format that McK employs. The firm wants to see exhaustive and creative approaches to specific problems, which more often than not do not fit into the classic case interview frameworks that were en vogue 10 years ago…

Again, this only applies if everything you say

  • adds value to the problem analysis
  • is MECE
  • is well qualified
  • includes a detailed discussion of your hypotheses at the end

The difference in format and way of answering a question is the reason why I recommend preparing very differently for McK interviews vs. other consultancies.

Read more about the McKinsey interview process and the McKinsey case interview specifically.

We can help you draft frameworks and communicate them properly

Good luck with your preparation! If you have any questions regarding how to structure MBB cases, the differences between McKinsey, BCG, or Bain, reach out to info@strategycase.com – we are always happy to help our candidates to start their consulting careers!

If you want to learn in great detail how to approach cases, draft a structure, and communicate them properly to the interviewer, check out our 40-part Ready-for-McKinsey interview academy, which includes McKinsey-specific examples of case study and all dimensions and stories of the PEI, or our individual and private coaching sessions. 9 out of 10 candidates who go through our 1-on-1 interview coaching program get the offer. We are consistently ranked as the best McKinsey and MBB coaches on PrepLounge.

the image is the cover of the ready for mcKinsey Case Interview Consulting video academy

McKinsey Interview Academy (Case and PEI)

SALE: EUR 249 / EUR 149

 

Leave a Reply

Your email address will not be published. Required fields are marked *