In the first two minutes of a case you should repeat the question back in your own words, ask two or three clarifying questions, take a short pause to structure, then present a tailored structure and say where you'd start. Doing this well sets the interviewer's first impression and gives you a roadmap for the rest of the case.
Why do the first two minutes matter so much?
Interviewers form impressions early. A crisp opening signals that you're calm, structured and focused on the client's actual problem. A rambling one forces you to recover for the rest of the case. Your opening structure also determines what data you'll ask for, so mistakes here compound.
What should you do in the first 20 seconds?
Listen and take notes
Write down the key facts: client, industry, geography, objective, any numbers and any time frame. Don't start structuring while the interviewer is still talking.
Summarise the prompt back
"Just to make sure I've understood: our client is a mid-sized UK supermarket chain whose operating margin has fallen from 4% to 2% over two years, and they've asked us to identify why and what to do about it. Is that right?"
This catches misunderstandings early and shows active listening.
Which clarifying questions should you ask?
Ask only questions that would change your approach. Good categories:
- Objective: "Is the goal to restore the 4% margin specifically, or to improve profitability generally?"
- Scope: "Are we looking at all stores, or a particular format or region?"
- Business model: "How does the client make money, mainly in-store grocery, or is online material?"
- Constraints: "Is there a timeframe, or are any options off the table, such as store closures?"
Two or three is usually enough. Avoid asking for data you'll need later, such as "What were costs last year?", at this stage, since you don't yet know why you need it.
How do you ask for thinking time?
Say: "Would you mind if I take a minute to structure my thoughts?" This is expected and normal. Use around 60–90 seconds. Longer silences can feel awkward, though norms vary by firm and interviewer. While structuring:
- Write the objective at the top of the page.
- Build three or four main branches tailored to the problem.
- Add two or three sub-drivers under each.
- Circle where you'd start.
How should you present your structure?
Signpost first
"I'd like to look at three areas: first..., second..., third..." The interviewer should always know where you are.
Explain why each branch matters
Don't just name buckets. Say what you'd test: "First, revenue: whether like-for-like sales have fallen, either through fewer customers or smaller baskets, perhaps because discounters have taken share."
Turn the page towards the interviewer
In person, show your structure. In virtual interviews, describe it clearly, and some candidates hold their page up to the camera if the format allows.
Prioritise and propose
Finish with a hypothesis and a starting point: "Given how aggressive discounter growth has been in UK grocery, my initial hypothesis is that we've lost volume to discounters. I'd like to start by looking at like-for-like sales and customer numbers. Do we have that data?"
What does a full two-minute opening sound like?
Prompt: "A European budget airline wants to know whether it should start flying long-haul routes."
Strong opening (abridged):
"So the airline currently flies short-haul only and wants to know if adding long-haul routes would be profitable and strategically sensible. Two quick questions: is there a target return or payback period, and would they buy or lease new aircraft for this?
[After the interviewer answers and a pause:]
I'd look at four things. First, market attractiveness: demand on candidate routes, price levels and whether low-cost long-haul has worked for others. Second, economics: revenue per flight versus costs, especially fuel, aircraft leases and crew, since long-haul cost structures differ a lot from short-haul. Third, capabilities: whether our low-cost model transfers, for example the need for different aircraft, crew rest rules and onboard service. Fourth, risks, including competitive response from incumbents and the effect on our brand. My hypothesis is that unit economics are the biggest question, because low-cost long-haul has historically been difficult, so I'd start there."
What are the most common opening mistakes?
- Diving straight into maths before understanding the objective.
- Generic buckets ("market, company, competition, financials") with no tailoring.
- Too many clarifying questions, which becomes an interrogation that delays the case.
- No prioritisation, leaving the interviewer to choose where to go.
- Mumbling the structure while looking at the page instead of the interviewer.
How should you practise your opening?
Drill openings separately from full cases. Do ten openings in a session: read a prompt, clarify, structure, present and prioritise, all inside two to three minutes. Record yourself to check clarity and pace. AI case practice tools like caize.ai are well suited to this because you can run many openings quickly and get immediate feedback on structure quality and clarity before investing in full mock interviews.
FAQ
How long should I take to structure?
Roughly 60–90 seconds is common. Ask for the time rather than thinking in silence without warning.
Is it OK to ask no clarifying questions?
Only if the prompt is completely clear. Usually at least one question about the objective is worthwhile.
Should I state a hypothesis immediately?
A tentative hypothesis after your structure is good practice, as long as you hold it loosely.
Does the opening differ in interviewer-led cases?
Slightly. The interviewer may ask "What would you look at?" directly, so keep the structure proportionate and expect them to direct the next step.
