Business case prep

Step-by-step guide to walk you through the entire business case prep process.

Includes frameworks, examples, common mistakes, and free materials.

Why a business case interview

You are given a business case interview to assess your problem-solving, analytical, and communication skills in a real business context. It simulares the challenges consultants face by presenting a business scenario and asking you to develop a solution. This exercise is done in real time, most likely in the recruiter's office, sitting across from 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 to give you a sense of what is expected. We will guide you through the process, step-by-step, in the sections that follow.

Structure of the business case

The business case usually takes 40-60 minutes, depending on the consulting company.

The interviewer will read a general statement like:

"Our client is a manufacturer of casts and supports used in correcting bone structure. They recently developed 3 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 to approach the problem.

Once you are done, you will start gathering information and data from the interviewer. You will take some time to structure these inputs and develop a response. After that, you will walk the interviewer through your thought process while you make the math calculations. You may also be asked a qualitative question for you to brainstorm (e.g. "How could our client increase the revenue per helmet?"). Finally, you will give a final recommendation response to the client.

You probably have many questions - that´s okey. In the sections below we give you specific guidance for each of these steps.

How to prepare

Step-by-step

This is a very detailed description of what happens during a business case.

It is written in a way that tries to solve all the questions at once. Be open and prepared for small twists during your interview.

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.

Part 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 for treating this. The device has 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 with your own words of the problem statement to ensure you understood it well

• Take a second to think if there are any key initial, high-level questions (max 3-4) you want to clarify to have a better sense of the client before moving forward. For example: "Apart from maximizing profit, does our client have any other key goal?" , "Where is this company located?", "Is this device new in the market?"

• If you don´t understand a concept in the statement, ask. 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?")

Part 2: Structuring your analyses (framework) (10 min)

After understanding the basics of the problem (section above), do not expect the interviewer to ask you anything else. It´s your turn to talk.

• Ask if you can take a minute to structure your thoughts (don´t take this for granted and don´t use the word "framework"), say "thank you" 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 is important that it follows an order (first, second, ...) and that it has a clear structure

  Example: 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 do 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; it has to be as realistic as possible. If your client is a medical manufacturer, use relevant industry terms (e.g. use the terms "patients" and "medicine" instead of "clients" and "products")

Step 3: Gathering data (5 min)

Once you are done addressing the statement (framework), do not 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 info, they will give it to you.

  
  

  Notes: 

  Macro: Market share > market (total and capturable) > willingness to pay

  Internal: Production volume > costs (fixed, variable)

  
  

  "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 device, package, etc.?"

Keep in mind that 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 all the data and information, follow these steps:

• Breathe profoundly. Here 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 (high-level). Follow a logic and order to make sure you don't get lost.

  
  

  For example, if you are discussing what the right price should be:

  
  

  "First, I will address the willingness to pay of clients and then the producing costs; finally, propose a price and use it to estimate profits"

• Walk them through the detailed steps:

  
  

  "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 Y. Then, I ...."

  
  

  When you are shown graphs, charts, or tables:

  
  

• Fists, take a couple of seconds to review it (don´t ask for permission)

• Second, share a quick summary of the content

• Third, mention any initial insights

• Fourth, explain how this data is helpful for finishing your exercise.

"Here I can see a table with the split of patients by age and geographical distribution and the estimated willingness to pay. At a 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 (...)"

• When you get to a final result, take a few seconds to think if the number makes sense (if you made a mistake, don´t panic; just tell them you are going to review your numbers), and also share your thoughts on the number (if it seems relatively high or low)

"So the estimated optimal pricing would be 20 USD. The number seems a bit high given that the market leader charges 18 and 25% of the patients are highly sensitive to prices".

Step 5: Brainstorming on what else (5-8 min)

After you are done with the math, it´s 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 do not sound numerical, but more like an invitation to just think.

• Ask if you can take a minute to structure your thoughts, say "thank you" and then write down your ideas

• Structure your ideas in one or two layers, so it is not just a long list of ideas:

  
  

  Bad (mere list of ideas): Raise price, invest in communications, explore discounts and referrals, do partnerships with pharmacies and distributors, etc.

  
  

  Good (one layer of structure):

  • (A) Increase sales per patient: idea 1, idea 2, idea 3

  • (B) Increase client base (more patients): idea 1, idea 2, idea 3

  
  

  Best (two layers of structure):

  • (A) Increase sales per patient

    • (A.1) More doses: idea 1

    • (A.2) Same doses: idea 1

  • (B) Increase client base

    • (B.1) Suffering from apoplexy: idea 1

    • (B.2) Suffering from other illnesses: idea 1

Step 6: Giving a final recommendation (3-5 min)

• Ask if you can take a few seconds to structure your thoughts and draft your answer

• Give a straightforward, short answer to the question the client had. Then, add additional considerations and/or relevant next steps.

"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)."

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 your answers sound like "copied and pasted".

A tip is to use a generic framework focused on the process of getting to the answer and then adapt it based on the case you are given with very relevant and specific examples and key concepts. 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 client´s additional 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: 

• In terms of competitive forces, I would focus on mapping other medical manufacturers offering the product and understanding if we should expect more competitors entering the market soon. Are there alternative treatments? What is our market share?

• In terms of the addressable market (i.e. volume of patients), it would be important to find estimations of the % of the population that suffers from this condition and % that is treated. It would be interesting to know if these % are changing significantly in recent years

• Finally, in terms of socio-economic factors, it´s 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 of death or life, but still it could be a factor to consider"

Note: These three subcategories (competition, client size and socio-economic issues) are relevant for most cases. You can, however, adapt it to make it even more relevant. For example, in this case, you may want to mention that an economic crisis doesn´t affect demand because it is a medical treatment, and instead focus on socio-cultural considerations (e.g. if it was AIDS, there may be a taboo surrounding going to the doctor for help thus affecting sales)

___

"Second, I would focus on understanding the client´s economics:

• I would review estimations of the volume of patients expected; specifically, those interested in being treated. I would investigate their costs; first fixed costs, such as A and B; and then variable costs, 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 doesn´t make sense to mention that you will consider the pricing because that is the answer you need to get to. You can 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 is possible - since this would affect the 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. Don´t include it if it doesn´t fit easily (you can replace it with "Other considerations").

Twists to this generic framework

If a case is about pricing:

• Make sure in the market forces you include the final buyer´s willingness to pay considerations.

• Don´t make the mistake of saying will you review the client´s pricing (figuring out the pricing is your job).

• Generally, pricing is set based on 3 considerations simultaneously: competitor´s pricing, client´s willingness to pay and internal costs (you need to cover these to be break-even)

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, break-even point 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 (e.g. innovative industries or operations in unstable countries...)

Formulas & Maths shortcuts

Business cases do not require you to know complex formulas. Generally, the ones below should be enough to handle any business case.

• 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 (for ex. pricing), you may want to review whether there are any other basic formulas involved.

In many cases, consulting firms will expect you do the Maths by hand (without a calculator). That means that you need to practice feeling comfortable that day. Notating the units (k, M) 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 Maths during business cases:

Math Drills | Fast Math Case Prep

Fast Math in Case Interviews

Case Interview Math (formulas, practice problems, tips) - IGotAnOffer

Consulting math: all you need to know (and how to practice)

Commons Mistakes

When connecting to the interviewer

• Don´t forget eye contact. Consulting isn´t only about solving problems; it´s about connecting with your client (or interviewer)

• Don´t (wrongly) assume that being professional equals being serious. You need to connect with the interviewer, and a smile can help. Also, try to project enthusiasm for the case. If you just seem to suffer, they won´t be excited about working with you down the road.

• Don´t be unprepared - bring paper, a pencil, and a calculator (if needed)

• Don´t ask the interviewer if you are on track or if your approach is correct. Assume it is and keep going; you need to look confident.

• Don´t believe the interviewer just wants to hear the final magic number. They want to know how you think and the process by which you get to the answer. Involve them!

• Don´t use generic terms when discussing the framework or diving examples. You need to show that you understand the client and the market. For example: in a medical context, "treatment" is better than "product," "patient" is better than "client," "hospital" is better than "shop," etc.

To get the problem right

• Don´t hold important clarifying questions for fear of sounding like a dummy. You need to have all the details to be able to get to the bottom of the problem.

• Don´t forget the key problem statement. Make sure you keep it in mind or revise your notes if needed. Never ask the interviewer what the question was!

• Don´t assume that you know what the client wants just because the statement includes some vague goal. You need to fully understand the main objective(s) of your client from the beginning. For example: "Is the goal of our client maximizing profit only? Are there any additional important goals?"

• When you get to a number, do not assume it is good. Take a second to think if it makes sense.

• If you make a mistake, don´t panic. You can say "I think I may have made a mistake. Let me review my math to make sure I got it right". What matters is that you realize it fast.

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