Case interview basics for consulting graduates

Offplication editorial team · Updated 24 October 2026

Editorial example · no professional reviewer endorsement claimed

A café is attracting more customers, but its profits are falling. What would you investigate first?

This is the kind of business problem you might encounter in a consulting case interview. Rather than testing how many business frameworks you can memorise, case interviews often explore how you structure an unfamiliar problem, analyse information and communicate a recommendation.

For graduates applying to consulting and strategy roles in Hong Kong, practising a clear problem-solving process can make challenging questions easier to approach. Below is a practical introduction to consulting case interviews, including a worked example with simple calculations.

What Is a Consulting Case Interview?

A consulting case interview is an exercise where you analyse a business problem and explain your reasoning to an interviewer.

Common case topics include profitability, market entry, pricing, business growth and operational efficiency. The format and level of difficulty vary by employer.

You may be asked to interpret data, perform calculations, identify the causes of a problem or recommend a business decision.

A strong response demonstrates structured thinking, sensible assumptions and clear communication rather than relying on a memorised answer.

Step 1: Understand the Business Objective

Before building a framework, clarify what the client wants to achieve.

For example, if a company says its profits are falling, you could ask:

• Are we investigating profit, profit margin or revenue?
• When did the decline begin?
• Does the problem affect all products or only some?
• Are there geographical, budget or time constraints?

Restate the objective in your own words so the interviewer can follow your approach.

Step 2: Build a Useful Case Interview Structure

Break the business problem into smaller questions that you can investigate.

For a profitability case, a useful starting point is:

Profit = Revenue − Costs

Revenue can be examined through customer volume and average spending. Costs can be separated into fixed and variable expenses.

This structure gives you a logical starting point, but you should adapt it to the information provided. Not every case requires the same framework.

Step 3: Work Through a Consulting Case Example

Imagine a fictional café in Hong Kong reports the following monthly figures:

Interview question: Why has the café’s monthly profit fallen, and what should the owner investigate?

Start by calculating the change in profit.

Previous profit = HK$120,000 − HK$100,000 = HK$20,000.

Current profit = HK$110,000 − HK$105,000 = HK$5,000.

Monthly profit has therefore decreased by HK$15,000, or 75%.

The decline comes from two directions: revenue has fallen by HK$10,000, while costs have increased by HK$5,000.

The next step is to understand why. Has the café served fewer customers? Has average spending declined? Have ingredient prices or staffing expenses increased?

These figures identify the problem but do not yet establish its underlying causes.

All figures are fictional and intended for interview practice only.

Step 4: Make a Recommendation Based on Evidence

A good recommendation directly addresses the business objective.

For the café example, you might say:

“Profit has fallen by 75%, driven by both lower revenue and higher costs. I would first investigate changes in customer volume, average transaction value and major expense categories. Once the causes are confirmed, I would prioritise actions with the greatest likely impact on profitability.”

This recommendation identifies the main finding, explains the next investigation and avoids claiming that an untested solution will work.

Common Consulting Case Interview Mistakes

Using a framework without adapting it: A structure should help you investigate the client’s actual problem, not become a script.

Rushing into calculations: First establish what the figures represent, then check your units and assumptions.

Giving unsupported recommendations: Separate what the available evidence shows from what still needs investigation.

Forgetting to communicate: Explain important reasoning steps so the interviewer understands how you reached your conclusion.

How to Practise Case Interviews Effectively

Choose a straightforward business problem and practise breaking it into logical components. Work through calculations without relying immediately on a calculator, then explain your findings aloud.

With a practice partner, try summarising your recommendation in under one minute. Ask whether your conclusion is clear and supported by the evidence.

As you improve, introduce more complex data, time limits and unexpected follow-up questions.