Updated: Jul 26, 2021
If you are serious about a career in management consulting, or are just curious about exploring it as an option, you would have come across the interview format the industry is known for – the case interview. A case interview is an interactive process where an interviewee solves a management consulting case – modeled after a real world consulting project or problem – in front of interviewers. Case interviews exist because they are the easiest way of simulating an actual consulting project scenario, and testing the candidate’s ability to solve real business problems in a structured manner.
There are various types of case interview questions, each represents different business scenario.
Do be aware that there are different formats of case interviews, including 1-on-1, group case, presentation case, etc. This article will focus on how to crack the most popular 1-on-1 case interview, although most of the tips are applicable for other case interview formats as well. Presented below is the typical flow of a case interview, and the tips for each stage of it.
Stage 1 - Case Prompt
At this stage, the interviewer will give a brief description of the case (usually a few sentences), and ask a vague question. The description of the business problem will usually contain some information of the client (e.g. “Fortune 500”, “pharmaceutical company”, etc.), and the situation the client is facing (e.g. “falling profit”, “customer attrition”). The question usually contains very little direction, such as “how do we proceed”, or “what can we do to help the client”.
1. Summarize the essence of the problem
Be succinct in the summary. Show that you understand the problem at hand, and are able to articulate it to the client. Showing understanding of the client’s situation is the first step towards solving the problem with the client, so show that you are a pro.
2. Clarify the goal
Do not assume that you know the best. Always clarify what the purpose of the case is. Is the client trying to grow revenue, reduce cost, drive profitability or capture market share? Be very explicit that you are thinking for the client, and solving the actual problem they want you to solve.
3. Ask for some time
Once you are clear about the situation and the goal, ask for some time from the interviewer. With the few minutes that the interviewer gives you, collect your thoughts and start developing your problem-solving framework.
Stage 2 - Develop Framework
The candidate develops the structure for solving the case. The structure needs to include an overall hypothesis, and a problem-solving framework (also known as an issue tree).
1. State your hypothesis
Again, be explicit. Show the interviewer that you are adopting a hypothesis-driven approach in your problem-solving. By coming up with a structure, you are implicitly developing hypotheses. Distil the main hypothesis and state it to the interviewer. Do not worry about it being right at this stage. It is meant to be revisited later.
2. Introduce your structure (and be MECE!)
Use your paper as a PowerPoint slide and walk your interviewer through your problem-solving structure. Remember this golden rule: mutually exclusive, collectively exhaustive. This means that different branches your structure should not overlap with each other, and together they should cover all possibilities. In reality, it is difficult to be truly exhaustive, so remember to prioritize the most important factors.
3. Customize your framework
Apply the hypothesis driven approach to derive the most useful and relevant buckets that help you solve the problem. Use the standard framework only as the starting point.
Step 3 - Framework Exploration
This begins the case-solving stage. At this stage, the candidate break down the case problem into smaller problems based on the structure introduced in the previous stage, and tackle each of the sub-problems. The purpose of this stage is to quickly isolate the most “valuable” sub-problem(s) to drill down, and eliminate the less relevant branches of the framework
1. Turn each sub-problem into a verifiable sub-hypothesis
Again, show that you are adopting a hypothesis-driven approach, by developing each branch or your problem-solving structure into a small hypothesis. With the hypothesis, asking for data will be very focused and effective.
2. Prioritize the sub-hypotheses
The interview is not a three-month project, so ask the most hopeful questions first. Prioritize the branches of your structure, and do not waste too much time on the ones that do not seem hopeful.
3. Think our loud
Guide the interviewer through your thinking process. If possible, walk him/ her through while you are going through the problem-solving structure. It is not easy, but doing so helps fill the gap of your response, and shows thinking capabilities.
4. Use process of elimination
Cross out branches that are disproved by data. If the interviewer says maybe we should be looking at other factors, move on.
5. Ask specific questions
Vague questions will only get vague answers, which may not be useful in solving the case at all.
6. Pay attention to interviewer’s hints
Other than asking you to move on, the interviewer may also try to guide you through the problem-solving. For example, he/ she may ask you to think of more factors contributing to a sub-issue, which suggests that this is an area worthy of more exploration.
Step 4 - Deep Dive
The candidate dives deep into the relevant branches to solve the case. In order to make informed recommendations, the candidate needs to ask for useful numbers/ exhibits/ qualitative information. The interviewer will look out for the crucial data analysis skills.
1. Segment the data
In order to arrive at the most effective recommendation, it is important to understand specifically what is the root of the problem. That’s why segmenting the data is crucial – it helps to find out what is the root cause. For example, if revenue is declining, which customer segment is causing the decline? Sometimes, it helps to ask the interviewer if the client has a method of segmenting certain data, rather than try to come up with your own way.
2. Treat your notes as “slides”
It is very useful to have some visual aid while explaining your findings, and the only thing at your disposal during the interview is the notes. Be clear with the note-taking, calculations and preliminary conclusions, and use them to help the explanation.
3. Structure your quantitative data
Structure the data you receive like an Excel spreadsheet. Walk your interview through the structure, and explain how you plan to analyze the data. Only start calculating after your interviewer agrees with you approach.
4. Do mini-synthesis
Answer the “so what?” from you data analysis. Give a mini conclusion where appropriate, e.g. to eliminate a branch after investigation, or to conclude that something is the root cause.
5. Revise the overall hypothesis along the way
Remember that the overall hypothesis is meant to be constantly updated. If at some point the data shows the original hypothesis is not valid, revise it and be very clear about it. This shows that you have not lost sight of the bigger picture.
6. Be creative
Show creativity where possible, but do not force it. Sometimes, an out-of-the-box idea could make you stand out from other candidates.
Step 5 - Synthesis/ So What
The candidates syntheses what he/ she has learnt about the case, and presents what the root problem/ key issue is. There may not always be time to do a separate overall synthesis, so it is important to draw mini-conclusions and demonstrate ability to think of the bigger picture.
1. Always answer the “so what”
Don’t repeat the obvious result from the data analysis, e.g. “a segment is declining”. Help the client think of the actual implications of a finding. For example, what does it mean to be losing in a particular segment? What is the level of severity given the size/ growth of the segment? What kind of initiatives should the client be considering to win them back?
2. Utilize analysis to take a stand
It is normal to feel that you do not have enough data to take a stand, and the interviewer knows it when there is no conclusive evidence. However, do not hesitate to give a conclusion. In reality, there is always going to be uncertainty in a project, but the client will not take “no conclusion” as an answer.
Step 6 - Recommendation
After the synthesis, the candidate provides the recommendations. Sometimes, the interviewer will prompt by saying, “I have a meeting with the client’s CEO in an hour, what should I tell him/ her?”
1. Have a clear recommendation
Give the client the most important conclusion first, before giving the evidence. Be very clear and concise with what you recommend them to do.
2. Use the pyramid principle
Communicate by starting from the tip of a pyramid, i.e. the conclusion/ recommendation. Then go down the pyramid by providing up to three supporting reasons. For each of the reasons, go down another level by providing up to three pieces of evidence.
3. List the risks and next steps
Do not stop at the recommendation. Tell the client what potential risks could be involved and how to address them. Finally, think of beyond the immediate problem. In reality, the client may engage you to solve a pressing issue, but it is up to you to turn the issue into opportunities, and start a relationship. So, tell the client what next steps he/ she can take.
1. Be confident
It is important to project a confident image. No matter how rigorous your analysis is, it is harder for the client to accept it if you do not appear confident in it. A confident candidate gives the interviewer the comfort that he/ she can put the candidate in front of a client.
2. Practice! Practice! Practice!
Do not underestimate the importance of practice, especially with people who are equally serious about consulting. To more experienced your case partner is, the more constructive feedback he/ she will be able to give you.
3. Note-taking skills
Practice your note-taking. Have a clear section for background information, for data and for conclusions. A clear visual aid helps you in your explanation.
4. 80/20 rule
Roughly 80% of the outcomes come from 20% of the causes. These could be applied to both the business problem at hand, and your time in solving a case. Hence, prioritize the issues on hand, and make sure you get to the 80%. Do not spent 80% of your time trying to figure out the 20% of the problem.
5. Get the right interview mentor
You are as good as the people around you. This is especially true in case practices. If your case partner is experienced, he/ she can help to bring your skills to a new level. At Case Prep Zone, all coaches have deep consulting industry experiences from the top consulting firms, and are ready and eager to help you land your dream offer in consulting. If you’d like to find out more, do not hesitate to contact us.