Passing the strategy consulting case study test

The case study is the ultimate test in strategy consulting firm interviews. Dreaded by candidates, the case study is an exercise that responds to precise consultant codes on which the candidate is evaluated.

July 27, 2022 Préparation

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Réussir l’épreuve de l’étude de cas en Conseil en stratégie - Couverture

Thecase study is the ultimate test in strategy consulting firm interviews. Dreaded by candidates, the case study is an exercise that responds to precise consultant codes on which the candidate is evaluated. Although it can take many different forms, the case study is a quick test of a candidate's ability to adopt the posture of a strategy consultant. Interviewers will often propose a case study drawn from an assignment they have worked on. This gives them the advantage of knowing the subject by heart. But don't panic: with the right preparation and a few tricks up your sleeve, any case study can be a success, and that goes for McKinsey, BCG, Bain and all the other firms.

Find out in this article what you need to know to tackle the case study test, as well as the best tips to make the difference.

What is the Strategy Consulting case study?

The case study: solving a strategy consulting assignment in less than 1 hour

The case study is an exercise generally based on a real strategy consulting assignment on which your interviewer, or at least the firm, has already worked. The interviewer will present you with a problem facing a company or organization. In 30 to 45 minutes, you'll have to put yourself in the shoes of a future consultant and come up with a solution. Your role will be to provide a structured response, analytically justified, and leading to recommendations for improving the initial situation. At the end of the case, you'll set out these recommendations in a concise, hard-hitting summary. From a distance, the case study may seem like a standardized exercise, but you must never lose sight of the fact that in reality it is first and foremost an interactive conversation. At every opportune moment, you need to make use of your interviewer, because unlike you, he knows his case by heart and will be best placed to help you solve it. Finally, it can happen that in some of your interviews, you don't get to the end of the case study. That's no problem, as 30 to 45 minutes is both a short time to solve the exercise, and plenty of time to evaluate yourself.

The different forms ofcase study: Interviewee-led vs. Interviewer-led

Before looking at the different types of case studies, it's important to review the two main forms.

  • Interviewee-led: You take the case from start to finish. This is the most common form of case, and the one that characterizes BCG interviews. In this form of case study, it's up to the candidate to take the lead and drive the resolution. As such, the interviewer won't give you much information, and will expect you to adopt a very proactive posture to solve the case. You'll have to identify the main issues, propose different avenues of analysis to solve the problem, and see the resolution through to the end.
  • Interviewer-led: Your interviewer leads the case by asking questions. This type of case is typical of McKinsey interviews. This time, the interviewer guides the case study by asking open or closed questions. But be careful not to fall into this trap: just because you don't guide doesn't mean you can't be proactive and take the drive to solve the case. This will be all the more appreciated by the interviewer, so in any case, always keep the same attitude.

Different types ofcase studies: profits, growth, new markets, market sizing

Throughout your preparation and interviews, you'll be working on various case studies. There are two main types: business case studies and market studies.

Réussir l’épreuve de l’étude de cas en Conseil en stratégie - Différentes familles d'études de cas

Sometimes, you'll have case studies that come together, such as an entry into a new market via an M&A acquisition. Also, you will very often have market sizing in your business case studies. For these reasons, it's essential to master the different types of case study.

Market research

  • Market-sizing: Estimating the size of a market in terms of volume or value for a specific product, on a given territory and within a fixed timeframe, or assessing a company's sales.
  • Brain-teaser: Test your ability to break down and structure a problem into less complex sub-problems. Note that this is very rare in strategy consulting interviews.

See also: Market sizing in 5 steps

Business case studies

  • Profit: Situation where companies are in financial difficulty and are unable to determine the cause and find solutions.
  • Growth: For a customer who wants to increase sales and asks you if it's possible, and if so, how?
  • Entering a new market/Launching a new product: Situation where the company already has an existing product in a given geography that is performing a priori well, and is looking to enter a new market, either with a new product to diversify its range, or by entering a new country or region.
  • Pricing: When a product has not yet been launched on the market and a price needs to be set, or when the product's price is not optimal and needs to be challenged.
  • M&A/PE: Financial cases, when a company is considering whether or not to acquire or merge with another, or when an investment fund is considering whether or not to invest in a company.
  • Response to competition: A company is faced with a change in its competitive environment, for example because of a new market entrant, or because a competitor has lowered its prices and started a price war.
  • Out of the box: Case studies that don't fit into any of these categories because they are highly atypical and will test your creativity and adaptability outside your comfort zone, e.g. public sector case studies.

For more information and examples of case studies, see our article : The different types of case studies

The 4 criteria for evaluating case studies in strategy consulting interviews

1. Be MECE in your structure and approach to the problem

The acronym MECE should become your watchword: Mutually Exclusive & Collectively Exhaustive. Every one of your answers must be structured in the MECE way, both your overall plan of approach and when you unfold your analyses. In practice:

  • Mutually Exclusive: All the elements of your answer structure must be distinct from each other, and must be able to answer the problem.
  • Collectively Exhaustive: The sum of all the elements in your answer structure should cover the whole problem and answer the question.

The MECE approach guarantees a complete and structured analysis of your case study.

2. Be irreproachable on the calculation part of the case studies

You don't need to be a mathematical genius to succeed in the case studies of strategy consulting firms. You'll rarely be asked to do more than add, subtract, multiply, divide or master percentages. However, stress can make the math part a real trap for candidates, so it's vital to practice as much as possible to ensure you're beyond reproach. You'll be tested on three aspects of the calculation part: putting the problem into a mathematical equation, solving it mathematically through your calculations, and interpreting your result.

3. Be business-minded and creative in your brainstorming

Business sense and creativity in the case study are qualitative elements of evaluation. Both are very important, as they enable you to stand out from the average candidate.

  • Business-sense: Your ability to adapt your approach to the case study, processing and interpreting information specific to the subject of the case study thanks to your knowledge. The Sector Sheets will help you to make rapid progress.
  • Creativity: Most often tested on open-ended brainstorming questions, creativity is your ability to imagine several solutions to a problem or specific question during the case, while taking into account the ins and outs of these solutions.

4. Be able to communicate orally and synthesize your work

The final evaluation criterion for the case study is the ability to communicate and synthesize. Just as when you were a strategy consultant, you need to be able to communicate clearly orally. Also, throughout the case, you need to learn how to synthesize your analyses, taking a step back on the progress of the problem resolution and confirming with the interviewer that you're heading in the right direction. Finally, most case studies end with a conclusion, where you'll need to demonstrate your ability to reiterate and summarize in a few seconds your analyses, results and final response to the problem.

For each of your case study training sessions, use this grid to assess yourself on the basis of these 4 evaluation criteria: MECE, quantitative, qualitative, communication & synthesis.

See also : How to join a strategy consulting firm

3 tips to make the difference in case studies during strategy consulting interviews

Adopt the posture of a strategy consultant

You need to adopt the posture of a strategy consultant throughout the interview, especially in writing, with clear, structured visual expression. Like a consultant, you'll need to think and write in slides. In concrete terms, instead of taking your notes in portrait format, take them in landscape format.

How to think and write like a strategy consultant in slides?

  1. To present your sheets in slide format, number them in the top right-hand corner and give them a title.
  2. Then, when taking notes, try to write clearly and legibly: write large, using a fine felt-tip pen, which is the preferred tool of consultants.
  3. Use a color scheme to highlight key elements. Your interviewers should be able to follow your reasoning even if your paper is upside down. They'll be all the more likely to enter the case with you and guide you if it's well presented.
  4. Whenever you feel it's relevant, don't hesitate to use comparison charts to keep your thinking structured and visual. Use tickmarks, diagrams or draw resolution trees. It's an exercise that will prove to your interlocutor that you see yourself as a consultant.
  5. When you've finished your analysis, you'll need to frame your results in a very academic way, with a large box and a different color. You need to be able to find them again at a glance.
  6. Finally, when you've finished writing a sheet of paper, don't put it just anywhere: arrange it logically in relation to the previous ones, with the number visible, so that you can find it easily.

The idea is that, in the end, your case study sheets should be slides, legible, structured and organized, like those of a strategy consultant.

Acquire the reflexes of the best strategy consultants: proactivity, conversation, spontaneity

Now that you've got the right posture for the casestudy, you need to acquire the reflexes of the best strategy consultants. First, on form:

  1. Be proactive: Formulate hypotheses and make sure your interviewer agrees with them. You'll need to recognize when it's your turn to make assumptions and when it's your interviewer's turn to provide information.
  2. Maintain an interactive conversation: The case study is solved interactively with the recruiter, who plays the role of your client, providing you with the information to which he or she has access. Remain attentive to your interlocutor: if you're cut off, it's because you're taking too long, or the information is not essential.
  3. Be spontaneous, but not too spontaneous : Even if you think you know the answer, or that you're capable of saying something clever by answering off the cuff, it's important to take a second or two to think things through. Occasionally, don't hesitate to ask your interviewer for a few extra seconds to structure your thoughts.

Acquire the reflexes of the best strategy consultants: SHARP, relative, results

If you've mastered the formal reflexes of strategy consultants, add those of substance and you'll definitely shine during your case study.

  1. Be SHARP: Use only the words necessary and sufficient to express your thoughts. In any case, even if it seems obvious to you, don't just say: "the market is growing strongly", which is a vague formulation, but rather: "The world coffee market has grown by 5% over the last three years".
  2. Use a point of comparison: A consultant always thinks in relative terms, in percentages and by comparison. You have various possible and relevant points of comparison: history, other countries, other products/services, the competition.
  3. Giving an intermediate result: At the end of each analysis you should give an intermediate result to give structure and fluidity to the resolution of your case study. A strategy consultant always knows what he's doing and where he's going, so you should too.

In a few words, for a successful case study, put yourself in the shoes of a consultant.

Beyond the technical knowledge required for each type of case study, the secret to success is to think and act like a strategy consultant. If you manage to speak the same language as your interviewer, without overdoing it, you've already done part of the job!

Read also: All you need to know about strategy consultants: assignments, careers, salaries

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