Case Interview Framework: A 5-Step Method for Consulting and PM Interviews
A case interview asks you to explain how you would solve a business problem. This guide uses five steps to organise that work. Adapt the structure to the question and check the assumptions before you calculate.
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Why this matters
Explain your reasoning so the interviewer can follow it and provide missing information. Define the problem, choose what to examine first, and check whether the evidence supports your first idea. End with a recommendation, its main risk, and the information you would still need. Hiring criteria differ by employer.
What to think about
These are fictional practice examples. Use your own experience and results in an interview.
- A profitability case where you open with an Issue Tree splitting revenue decline from cost increase before pulling any numbers from the interviewer.
- A market-sizing question where you state your approach and key assumptions out loud before calculating, so the interviewer can redirect if your structure is off.
- A go-to-market case where you frame a hypothesis in the first 60 seconds: 'My hypothesis is that the addressable market is large enough but the go-to-market motion is wrong—let me test that.'
- A pricing case where you structure around value-to-customer, competitive benchmarks, and cost floor before asking for any data.
- A growth case where you issue-tree the revenue formula and then prioritize which branch to drill into based on where the client has leverage, rather than exhaustively covering everything.
The framework
Step 1: Restate the problem and ask for missing definitions. Step 2: Break the problem into parts that you can examine. Step 3: State an initial hypothesis and the assumptions behind it. Treat it as something to test. Step 4: Ask for relevant data, explain the calculations, and revise the hypothesis when needed. Step 5: Recommend an action, explain the evidence, and name the main risk and next check.
Common mistakes
- Jumping into calculations before building a structure. Math without structure is data without meaning, and interviewers will interrupt or mark you down for it.
- Skipping the hypothesis step. Saying 'let me gather more data first' signals bottom-up thinking. Top consulting firms explicitly train for hypothesis-first reasoning.
- Treating the case like a quiz with one correct answer. Cases are ambiguous by design. The interviewer rewards your reasoning process and communication, not finding the 'right' number.
- Exhaustively analyzing every branch of your issue tree instead of prioritizing. Identify which branch is most likely to be the problem and go there first with explicit reasoning.
- Summarizing instead of recommending at the close. 'In summary, revenue is down 15 percent due to pricing' is a summary. 'My recommendation is to raise SMB prices by 8 percent in Q1 while protecting enterprise contracts' is a recommendation.
Bad answer vs strong answer (scored)
The example scores illustrate this guide’s feedback. They are not employer ratings or predictions of a job offer.
The question
Your client is a mid-size airline. Profits have declined 20 percent over the last two years. How would you approach this?
Weak answer
I'd look at revenue and costs. Revenue could be down because fewer people are flying or because ticket prices are lower. Costs might have gone up. I'd want to see their financial statements to understand the numbers better. Fuel costs are usually a big driver for airlines. I'd also look at what competitors are doing.
What's wrong
- No structure is stated before diving in. The candidate lists ideas rather than building a framework, so the interviewer cannot follow the logic or redirect efficiently.
- No hypothesis is formed. The candidate defers to 'I'd want to see the data' rather than leading with a directional view, which is the core skill being tested.
- The close is absent. There is no synthesis or recommendation—the candidate describes a process of looking at things rather than demonstrating structured problem-solving with a point of view.
Stronger answer
Let me restate: profits are down 20 percent over two years—I want to confirm that's operating profit, not net, and whether this is industry-wide or specific to this airline. Assuming it's company-specific, I'd split the issue tree into revenue decline and cost increase. My hypothesis upfront: given that the airline industry recovered post-2022, this is more likely a cost problem—specifically fuel or labor—than a demand problem. I'll test the revenue branch first to rule it out: load factors, yield per seat, and route mix. If revenue is stable, I'll move to costs: fuel hedging, labor contracts, and maintenance. Based on what you've told me, I'd recommend we start with cost structure. What does their fuel-cost-per-ASM look like versus peers?
Related practice
Quick answers
Do I need to memorize case frameworks like the 4Ps or BCG matrix?
Knowing standard frameworks as starting points is useful, but reciting a memorized framework robotically is a red flag that experienced interviewers immediately notice. The 4Ps, profitability framework, and BCG growth-share matrix are useful mental checklists, but they rarely map perfectly to any real case. Interviewers want to see you build a structure that is specific to the problem at hand, using standard frameworks as inspiration that you then customize. A candidate who builds a case-specific issue tree from first principles—even imperfectly—often scores higher than one who applies a memorized framework that does not quite fit the situation, because it demonstrates genuine structured thinking rather than pattern-matching.
How important is mental math in case interviews?
Practise accurate calculations and explain your assumptions. Say how you arrived at an estimate, use units, and check whether the result is plausible. Follow any instructions the employer provides about calculators or case format.
What's the difference between a case interview at a consulting firm versus a PM interview?
Consulting case interviews focus heavily on financial modeling, market sizing, profitability analysis, and operational recommendations. The grading is rigorous and interviewers have detailed rubrics. PM case interviews shift toward product strategy, user empathy, prioritization trade-offs, and go-to-market thinking. The 5-step framework applies to both, but the PM version weights the question 'who is the user and what do they actually need' much more heavily than pure revenue-and-cost analysis. PM interviewers also evaluate whether you can make a product decision under ambiguity without the benefit of a complete dataset—which is closer to the daily reality of the job.
Can I structure a case interview without saying the framework name out loud?
Yes—and at top firms, not naming the framework is often stronger. Saying 'I'll use the profitability framework' signals pattern-matching. Building a custom issue tree that happens to include revenue and cost branches—without announcing what it's called—signals genuine structured thinking. The interviewer cares about the quality of your decomposition, not whether you labeled it correctly. Where candidates go wrong is trying to silently apply a memorized framework without vocalizing the structure at all. Verbalize the branches: 'I'd split this into two sides—revenue drivers and cost structure—and within revenue I'd look at volume versus price.' That is a live structure, not a labeled framework, and it lands better.
How do I practice case interviews effectively?
The single best practice method is live sessions with real-time feedback—not solo reading of case books or watching YouTube walkthroughs. You need to practice speaking your structure out loud under time pressure, handling unexpected data from an interviewer who may redirect you, and synthesizing a recommendation with thirty seconds left. Solo prep builds knowledge but not the skill of thinking under pressure while communicating clearly. Odin's AI mock interviewer simulates the interactive pressure of a real case session and scores your structure, hypothesis quality, and recommendation crispness on every attempt—so you build the feedback loop that solo practice cannot provide.