How to ace your case study interview

Articulating your thoughts during your case study interview could bring you a giant step closer to getting hired.
Making your thinking process transparent is particularly important.

Why do consultancies use case study interviews?

Case studies test you in all manner of ways so they are one of the best – and fairest – methods of seeing a candidate ‘in action’. They are designed to evaluate how you process information, solve problems and react to new and surprising situations, as well as showing how you work within a team. Individuals or a small group of candidates are presented with a business problem and then given time to evaluate the information and brainstorm a solution. Case studies can be on almost any topic. OC&C Strategy Consultants says: ‘The cases can be on any topic, from the size of the diaper market in the Netherlands to how many tennis balls would fit in Wembley Stadium, to a business strategy topic, involving company financial data and graphs.’ Remember, as Bain & Company says, ‘There is no one ‘’right’’ answer. Case interviews should be thoughtful dialogues about potential approaches to solving a tough business problem.’

What to do in advance

Read the firm’s graduate recruitment literature and check its website to see if it has sample case studies (the vast majority of consultancies do). Have a look at recent press releases to get a feel for the type of work it’s involved with as well as what industries it works across. Read the business pages of newspapers and imagine one of the businesses to be your client. How would you advise them? What would you base your recommendations on? What factors would you and your client need to consider before proceeding to the next step? Also check with your careers service as many run workshops and presentations on how to prepare successfully for case studies and assessment centres.

Almost every graduate who offered advice on case studies via TARGETjobs Inside Buzz stressed the need to practise in advance. ‘Know the basic structure of case questions. Learn how to talk someone through your reasoning so that you voice assumptions you are making, and therefore find it easier to go back and challenge these assumptions,’ said one BCG applicant.

Advice from consulting firms

Through our research of top consulting firms the TARGETjobs team has come across some valuable nuggets of advice for succeeding at case study interviews, such as:

  • 'Expect maths: be prepared both to set up the analytics and do the maths. We want to see your comfort with numbers’ (Bain & Company)
  • Apply a structured approach to the problem; focus on the most important issues’ (Roland Berger Strategy Consultants)
  • ‘Don’t panic if the answer is not apparent’ (Boston Consulting Group)
  • 'Do not feel pressured to provide an answer immediately - take your time, work through the issues, and organise your thoughts’ (OC&C Strategy Consultants)
  • ‘Be attentive to cues your interviewer may give. How will the new information change your analysis?’ (Oliver Wyman).

Thinking out loud

The TARGETjobs team has been struck by a common thread – almost everyone we spoke to stressed that applicants should talk through their thought process with the interviewer. As L.E.K. Consulting puts it, ‘Formulate hypotheses – share your thought process as information is revealed.’ It’s a bit like making sure you show your calculations in a maths exam – it’s not enough just to come up with the answer. Given that case studies tend not to have ‘right’ or ‘wrong’ answers anyway, making your thinking process transparent is particularly important. The person interviewing you must be able to understand how you reach your conclusions – how you’ve broken the problem down, analyse information and structure conclusions. McKinsey & Company points out: ‘Someone whose answer is strategically closer to a “right” answer – but who arrived at it with superficial insight and a flimsy rationale – will not do as well as someone whose answer might be more off the mark because they don’t have the business background, but whose thinking is cogent and well supported.’

If you're in a group...

If you’re working in a small group divide the tasks – you’ll get through them far quicker. There may be different personalities in your group and recruiters will be watching to see how you interact. They will also be looking for evidence of leadership and teamwork. Don’t dominate proceedings but do pitch in and contribute where appropriate. It’s important to be yourself rather than play to a type.

Expect the unexpected

Additional information may be sprung on you so be prepared. Interviewers will be looking to see how you deal with the unexpected as well as how flexible you are with processing last-minute information. Ask if you’re unsure about something. Asking clarifying questions such as ‘Does that make sense?’ to the interviewer, will ensure you’re on the right track and shows self-awareness.

Example case studies

We can’t tell you exactly which case study you’ll face, but we can give you a couple of examples of what it might be like:

Expanding a business

Your client is a global organisation that manufactures and distributes a wide range of chocolate products. They have two ideas to expand the business: either to introduce a new range through existing distribution channels or move into a completely new business, which will involve building a set of retail stores. To approach this, you will need to compare the returns of each of the different investments and decide which will be the better solution for the business. Make sure you can explain the reasoning behind your decision.

Increasing a supermarket's profitability 

A supermarket chain has noticed a decline in its profitability. They have hired you to find out why this is and to recommend and implement a solution. You’ll need to work out why there is a decline in profitability – for example, is it specific sites or the entire chain’s performance that is suffering? Once you have identified the problems, work out a cost-effective solution that will allow the supermarket to address each in turn.