Business case prep
- Rebeca G
- Aug 1
- 15 min read
Updated: 7 days ago
Step-by-step preparation to guide you through the entire business case process.
Includes frameworks, examples, common mistakes, and free materials.
Why a business case
You are given a business case interview to assess your problem-solving, analytical, and communication skills in a real business context. They simulate the challenges consultants face with by presenting a business scenario and asking you to develop a solution. It is an exercise done in real time, most likely in the recruiter's office, sitting next to the interviewer. This is useful to test your abilities and potential to do client-facing roles under pressure.
Below are some mock business case interviews for you to get a sense of what to expect. In the sections below we guide you through step by step.
Structure of the business case
The business case usually takes 40 to 60 minutes, depending on the consulting company. They will read a general statement like:
"Our client is a manufacturer of casts and supports used in correcting bone structure. They recently developed three new baby helmets and would like to know if they should launch one or more of these products onto the market. Specifically, is a target profit of $1 million a year reasonable?"
After clarifying any questions you may have, you will be expected to develop and discuss a framework designed to solve this problem.
Next, you will start gathering information and data from the interviewer. You will take some time to structure the inputs and develop a response. After that, you will walk the interviewer through the process while you make the necessary calculations. You may also be asked a quantitative question to prompt brainstorming (e.g. "How could our client increase the revenue per helmet?"). Finally, you will summarize your conclusions for the client.
Duration | Phase/Step | Key Action | Goal & Output |
3–5 min | Part 1: Understanding the Problem | Ask Clarifying Questions (max 3–4) and recap the problem statement in your own words. | Ensure full alignment on the client's goal (e.g., maximize profit) and key context. |
10 min | Part 2: Structuring Your Analyses (Framework) | Ask for Time (1–2 min silence), then walk the interviewer through your MECE (Mutually Exclusive, Collectively Exhaustive) structure. | Develop a logical, customized roadmap for solving the client's problem. |
5 min | Step 3: Gathering Data | Ask for Specific Data (Macro and Internal) by strictly following the structure you just laid out. | Gather necessary quantitative and qualitative inputs to perform the analysis. |
20 min | Step 4: Addressing the Quantitative Problem | Structure your math approach (high-level), then walk through calculations aloud, checking assumptions and initial results. | Solve the core numerical problem and derive a data-backed initial answer. |
5–8 min | Step 5: Brainstorming (Qualitative) | Ask for time (1 min silence), then structure your ideas into 1–2 logical layers (e.g., "Increase Sales" / "Increase Client Base"). | Demonstrate creativity and structured problem-solving for non-numerical twists. |
3–5 min | Step 6: Giving a final recommendation | Ask for time (a few seconds), then synthesize the answer. | Deliver a straightforward answer, backed by data, plus considerations and next steps. |
You probably have many questions - that´s fine. In the sections below, we provide specific guidance for each of these steps.
How to prepare
Below are a few steps that will help you get started when you have no experience with business cases. If you already have experience, you may want to skip this section and go directly to the mock practice.
Start by scanning key consulting websites to understand the dynamics of the case and expectations. Review a couple of videos to get a sense of what happens during the case (you can find these below, in the "Relevant materials" section). Don´t jump directly into practice.
Read through a few business cases to understand how you are expected to structure and answer the questions.
Start going through a few cases without taking into account the time it takes you to resolve the questions. Focus on:
(1) Structuring the framework
(2) Structuring the approach to the quantitative question (the math section)
(3) Practicing math
Once you feel comfortable with the practice, start doing mock cases (giving the answer aloud and taking time into consideration).
Once you feel comfortable with the mock cases, find a partner to practice and get feedback to refine your answers (read the "Network" section below)
Step-by-step
This is a very detailed description of what happens during a business case.
It is written in a way that answers many questions you may have.
Step 1: Understanding the problem (3-5 min)
Recruiter: "Our client is a manufacturer of medical devices used to treat apoplexy. They recently launched a new device with two components—an injector and a disposable cartridge. They would like to know how they should sell these products to maximize profit. What should they do?" (Statement)
Listen carefully and take notes
This statement is the most important piece of information - what your client wants. Make sure you remember this throughout the case (sometimes people forget when they focus on the math)
Do a brief recap in your own words of the problem statement to ensure you understood well
Take a moment to think if there are any key high-level initial questions (max 2-3) you want to clarify to have a better sense of the client before moving forward.
E.g. "Apart from maximizing profit, do they have any other key goal?" , "Where is this company located?", "Is this device new in the market?"
If you do not understand a concept in the statement, ask for clarification. It is difficult to solve a problem if you do not understand what the client does
E.g. You mention the medicine is for apoplexy. Can you explain what this means?)
Step 2: Addressing the statement (framework) (10 min)
After understanding the basics of the problem (section above), do not expect the interviewer to ask you anything else; it is your turn to talk.
Ask if you can take a minute to structure your thoughts (do not take this for granted and avoid using the word "framework"). Say "thanks" and then draw the structure of your framework in silence (1-2 min)
When you have it (read "Deep dive: framework" below), walk the interviewer through it, explaining how you would approach the process of solving the client´s problem (5 -8 min). It´s important that it follows a logical order (first, second, ...) and that it has a clear structure (competitors -> clients -> ...).
E.g. First, I would like to understand what is happening in the market, since this is important to set the right pricing. Are there many competitors and alternative treatments or we have the only one? Also, what is the current market size of our client? Do they need our treatment to survive or just to reduce pain? That affects the willingness to pay. Second, I would look into the manufacturer's financial information to understand the costs (....). Finally, I would do a risk assessment of (...)
Avoid using generic words. If your client is a medical manufacturer, use the term patient instead of "client" when referring to the end-user.
Step 3: Getting more inputs (5 min)
Once you are done addressing the statement (framework), don´t wait for the recruiter to say anything. Go ahead and ask for data following the framework steps you just developed. Make sure you follow an order (sample below). If the recruiter has this information, they will give it to you.
So, first, I want to know the competitive forces. Do you have information about the number of competitors and market share?
Do you have data about the number of patients suffering from this condition, and which % would be willing to pay for a treatment?
Do you have information about how much they are willing to pay?
Do you have information about the costs of producing the vaccines? I am assuming the investment made is already a sunk cost. But what about fixed costs such as the manufacturing building or staff and variable costs such as the two components of the vaccine, package, etc.?
Note: Some companies do business cases where the applicant is supposed to take the lead 100% and ask all the questions to get to the final answers. Other companies will give you more guidance and walk you through the different sections. In reality, the majority of them are somewhere in the middle. So just be prepared and assume you lead, since this is usually more difficult (and also, it is awkward if you just go quiet waiting for the interviewer to say something).
You can learn more: video, web.
Step 4: Addressing the quantitative problem (20 min)
Once you are done with collecting more inputs, follow these steps:
Ask if you can take a minute to structure your thoughts, say "thanks" and then write down the process you will follow to get the answer
Take a deep breath. This is where most people panic or get confused and forget what the main statement (client´s problem) is.
Tell them how you are going to solve the problem. Follow a logic and order to make sure you don't get lost. For example:
For example: "If you are discussing pricing, first address willingness to pay of clients, then production costs; finally, propose a price and use it to estimate profits"
For example: "If you are discussing profitability, first estimate the client's volume (Q), then pricing (P), and finally costs, following the formula Profit = (P x Q) - Costs"
Sample approach "To answer the client´s question, I will do three things: First, I will estimate the willingness to pay of patients to have as the main pricing input. Second, I will estimate the total cost per treatment (to ensure that is above the price patients want to pay). Finally, for the recommended price, I will estimate the total annual profits, so the client has a more accurate answer.
So, for the willingness to pay - I have 5 segments, each of them with a different price. If I multiply X by Y .... i get Z. Then, I ...."
It´s common that the interviewer shows you some graphs, charts or tables. What to do?
First, take a few seconds to review it
Second, share a quick summary of the content
Third, mention any relevant insights
Finally, explain how this data is helpful for solving the problem
Sample answer: "Here I can see a table with the split of patients by age and geographical distribution and the estimated willingness to pay. At first glance, I can see there is a direct correlation between age, living in the city and willingness to pay. That seems reasonable as older people in cities may have a higher average income. This data is useful because it tells us what the pricing should be if we could perfectly segment all the patients (...)"
Step 5: Brainstorming on what else (5-8 min)
After you are done with the Maths, it is possible you are asked a qualitative question for you to brainstorm. They want to test your structure, capacity to do problem-solving and be creative.
Recruiter: "What can our client do to increase the willingness to pay of patients?"
These are questions that don´t sound numerical, but more like an invitation to just think.
First, ask if you can take a minute to structure your thoughts, say "thanks" and then write down your ideas
Second, structure your ideas in one or two layers, so it is not just a long list of ideas:
Structure Example | Bad (Mere List) | Good (One Layer of Structure) | Good (Two Layers of Structure) |
Ideas | Raise price, invest in communications, explore discounts and referrals, do partnerships with pharmacies and distributors, etc. | (A) Increase sales per patient: idea 1, idea 2, idea 3 (B) Increase client base (more patients): idea 1, idea 2, idea 3 | (A) Increase sales per patient (A.1) More doses: idea 1 (A.2) Higher price: idea 1 (B) Increase client base (B.1) Suffering from apoplexy: idea 1 (B.2) Suffering from related condition: idea 1 |
Step 6: Giving a final recommendation (3-5 min
Recruiter: "So, what would you tell the client?"
First, ask if you can take a few seconds to structure your thoughts and draft your answer
Second, give a straightforward, short answer to the question the client had. Then, add additional considerations and/or relevant next steps.
Sample answer: "Our client should sell the product at a price of USDX/ unit to maximize their profit, for a total of USD Y in yearly revenue (short answer).
This price recommendation is considering that there is no option to segment patients based on willingness to pay, and that no relevant competitors enter the market in the short-term (considerations).
As next steps, I would explore piloting a test in a limited location or with a sample of patients, as well as investigate the option to begin selling other medical products that could be relevant to this segment, such as monitoring devices (recommendation)"
It´s important to keep in mind that preparing business cases isn´t about just memorizing steps and frameworks. It´s about internalizing the skills that are needed during the case. From time to time, you will find interviewers who ask questions for which there is not a specific framework. You will need to feel comfortable with developing solid frameworks on the spot.
I was asked this during a McKinsey interview (final round).
"A distant relative just passed away. He left you a tennis court in the middle of the city. What would you do?"
Deep dive: The Framework
You will find plenty of books and online resources focused on frameworks. They are useful, but generally it isn't very practical to memorize dozens of them- and you risk making it sound like "copied and pasted" the answers.
A good tip is to use a generic framework focused on the process of getting to the answer and then tailor it based on the case you are given. This is useful because it makes you sound more action-oriented and already gives you a starting point to address any case problem.
Below is the general structure, which works well for the majority of cases.
First, investigate market forces.
Second, understand internal client/ project's economics.
Third, investigate additional client considerations
Finally, consider risks (if applicable)
Step | Core Investigation | Details & Focus Areas (The Mock Response) |
1. Market Forces | Understand the External Environment | Addressable Market Competitive Force Socio-Economic Factors |
2. Internal Economics | Analyze the Client's Financials | Financials: Revenue/Costs Investment |
3. Other Considerations | Identify Internal Synergies/Factors | Product Portfolio Strategic fit Partnerships ... |
4. Risks | Assess Potential Obstacles | Reputation Legal/Regulatory Other |
This is a mock response:
First, I would like to investigate what is happening in the market:
Competitive forces: I would focus on mapping other medical manufacturers offering the product and understanding if we should expect more actors entering the market soon. Are there alternative treatments? What is our market share?
Addressable market (i.e. volume of patients): It would be important to find estimations of the % of population that suffers from this condition and % that is treated. It would be interesting to know if this % are changing significantly in recent years
Socio-economic environment: It is important to consider if we are in a stable economy, or we expect any downward trend. I assume the demand for treatment should be quite stable because it may be a matter or life or death, but still, this could be a factor to consider.
Note: These three subcategories (competition, market size and socio-economic issues) are relevant for most cases. You can, however, twist it to make it even more relevant. For example, in this case, you may want to mention that an economic crisis does not affect because it is a medical treatment, and instead focus on socio-cultural considerations (e.g. if it was AIDS, there may be taboo surrounding going to the doctor for help, thus affecting sales)
Also, depending on the case, you may need to replace some sections, change the order or even build one from scratch.
___
Second, I would focus on understanding the client's economics:
I would review estimations of volume of patients expected. specifically, those interested in being treated
I would investigate their costs; first fixed, such as A and B; and then variable, such as Z and Y, and also the investment made so far. I will consider the investment cost a sunk cost since the treatment is already fully developed.
Note: In this case, it does not make sense to mention that you will consider the pricing because that is the answer you need to get to. You skip that part.
___
Third, I would consider other internal factors, such as:
Other medical products in the portfolio, to consider whether cross-sell exists or it´s possible, since would affect sales strategy and pricing
Potential partnerships with distributors which can influence costs thus pricing
Note: These are just some examples that are useful to have at hand. Based on the case, you may come up with different ones
___
Finally, I would consider any risks associated with the pricing, such as:
Reputational damage if pricing is considered very high
Legal restrictions to set or change the pricing
Also: Pricing cannibalization, lack of effectiveness of the treatment, etc.
Note: There are cases where the risks section may not fit. Do not include if it does not fit easily.
***
Twists to this generic framework
If a case is about pricing:
Include the final buyer's willingness to pay considerations in the market forces section.
Don´t make the mistake of saying you will you review the client´s pricing (figuring out the pricing is your job).
Generally, pricing is set based on three considerations simultaneously: competitor´s pricing, client´s willingness to pay and internal costs (you need to cover those to be breakeven)
If a case is about profitability, an investment or a decision go/no-go:
When discussing the internal economics, mention that you plan to estimate the ROI, breakeven or a similar metric
When discussing other considerations, consider mentioning that you want to map any potential alternative projects/ investments to understand opportunity costs
In risks, you may want to mention the point of whether the client has related investment (know-how), and the risk-level associated to that industry (for ex. innovative industries or operations in unstable countries...)
Formulas & Maths shortcuts
Business cases do not require you to know complex formulas. Generally, the ones listed below should be enough to handle most business cases.
Revenue = Volume x Price
Cost = Fixed cost + variable cost
Profit = Revenue - cost
Profitability = Profit/ Revenue
ROI = Annual profit/ initial investment
Breakeven = Initial Investment / Annual profit
Breakeven = Revenue - Costs = 0; X = ....
Net profit vs Gross Profit vs operational profit margin
Growth rate = (new %- old %)/old % x100
Rule 72 = for estimating the double time of an investment (how long it takes to double the value). Divide 72 by the annual interest rate (%) to estimate the doubling time. For ex. if the growth rate is 6%, the investment doubles in 12 years (72/6)
If your target company is specialized in a certain area (e.g. pricing), you may want to review whether there are any other basic formulas involved.
In many cases, consulting firms will expect you to do the Maths by hand (without a calculator). That means you need to practice to ensure you are comfortable on the day of the interview. Notating the units (K for thousands, M for millions) for large numbers, asking if you can round, and memorizing 1/2, 1/3, 1/4, ...1/9 are examples of tips that can save you that day. Here are some websites that give you free tips on how to be better with math during business cases:
Math Drills | Fast Math Case Prep
Case Interview Math (formulas, practice problems, tips) - IGotAnOffer
To get the problem right
Avoid Doing This | Recommendation |
Do not forget eye-contact. | Maintain eye contact. Consulting is about connecting with your client (or interviewer), not just solving problems. |
Do not (wrongly) assume that being professional equals being serious. | Smile and project enthusiasm. Being professional doesn't mean being serious. Show genuine excitement for the case; if you seem to suffer, the interviewer won't be excited to work with you. |
Do not be unprepared - paper, pencil or a calculator | Be prepared. Always have your paper, pen/pencil, and a calculator ready before the interview begins. |
Do not ask the interviewer if you are on track or if your approach is correct. | Do not seek validation. Assume your approach is correct and keep going; confidence is key. |
Do not believe the interviewer just wants to hear the final number. | Involve the interviewer. They want to know how you think and the process by which you reach the answer, not just the final number. |
Do not use generic terms when discussing the framework or giving examples. | Use client-specific language. Show market understanding by using precise terms. E.g. use "treatment" instead of product, "patient" instead of client, and "hospital" instead of shop in a medical context. |
Avoid Doing This | Recommendation |
Do not hold important clarifying question for fear of sounding dummy. | Ask clarifying questions early. Don't hold back important questions for fear of sounding uninformed. You need all the details to get to the bottom of the problem. |
Do not forget the key problem statement. | Remember the objective. Keep the key problem statement in mind, or revise your notes if needed. Never ask the interviewer to repeat the main problem statement |
Do not assume that you know what the client wants just because the statement includes some vague goal. | Verify the client's goals. Don't assume you know the objective. Fully understand the main goal(s) of your client from the beginning (e.g., "Is the goal strictly maximizing profit, or are there additional important objectives?"). |
When you get to a number, do not assume it is correct. | Sense-check your numbers. When you reach a calculation, take a second to think if the number makes logical sense (the "sniff test"). |
If you make a mistake, do not panic. | Handle mistakes calmly. If you realize you've made a math error, do not panic. State clearly: "I think I may have made a mistake. Let me quickly review my math to ensure I got it right." What matters is that you realize it quickly. |
Networking
Preparing business cases is often easier for people with connections in a consulting firm. Why? They can get first- hand guidance (like the advice above) and, more importantly, use those connections to practice mock interviews.
How to leverage connections
If you know someone who works at a consulting firm, ask them for a favor: a 45-minute mock case run-through (when you already feel you are 99% ready)
If you don´t know anyone, it is okay. There is plenty of material to read (see relevant links below)
Ultimately, the most important step is to find people to do mock practice with—either current consultants or other candidates who are in the same application process as you.
If you don't know any consultants:
Reach out on LinkedIn. Contact people who hold a similar position to the one you are applying for, even if you don't know them (read here for more detail).
If you want to find other candidates to practice with:
Use platforms and forums to find candidates.
Structure your sessions: Usually, you agree on having a videoconference and doing two mock cases. First, one person is the interviewer, and then that same person becomes the candidate. This closely resembles a real interview
Tips for effective practice:
This is recommended when you already know the structure and have done some mock cases while keeping track of the time.
Try to choose a partner who is at a similar level of practice (e.g. +10 mock cases)
Practice with more than one partner, so you get different types of feedback
Ask case partners for specific types of cases that you need to work on (e.g. different industries)
Prepare a case to give to your partner, so your feedback is better, and you add value to them
Where to find partners
You can find groups dedicated to consulting prep on LinkedIn, Facebook or similar
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