Hey there,

McKinsey cases are a bit different and are not about getting through the case for the interviewer but collecting enough relevant data points. As such, you will go through a series of (sometimes loosely) connected questions, and more often than not the case just ends randomly without a recommendation.

Answering more questions is not necessarily better; rather focus on answering every question exhaustively and to the best of your abilities.

Let's break it down below in a bit more detail:

1. The difference between a McKinsey case and a non-McKinsey case first and foremost lies in the interviewer-led format as you are aware. Every case you have in this case book can be asked from an interviewer-led perspective.

In the McKinsey interview you will have to answer three different questions types - broadly speaking:

• Structuring
• Exhibit Interpretation
• Math

While in candidate-led cases, they should arise naturally when you drill down into your structure, in McKinsey interviews, the interviewer will bring them up in succession.

2. The second big difference lies in the nature of questions asked at McKinsey. At the core, McKinsey wants to see creative ideas communicated in a structured manner, the more exhaustive the better.

As a result, McKinsey cases will usually be very creative in nature and not something that can be solved by looking at industry frameworks or industry trends. This also means that there are no right or wrong answers, just good or bad answers (or exceptional answers for that matter).

Be aware that frameworks were applicable in the 2000 years, the era of Victor Cheng and Case in Point. McK has long caught up on this and the cases you will get during the interviews are tailored in a way to test your creativity and ability to generate insights, not remember specific frameworks.

3. The third big difference is how to answer the questions in a McKinsey interview. Since the interviewer guides you from question to question, you need to be in the driver's seat for each question and treat each almost like a mini case in itself.

Your goal should be to come up with a tailored and creative answer that fits the question. The framework should - broadly speaking - follow these three characteristics:

• Broad
• Deep
• Insightful

The firm wants to see exhaustive and creative approaches to specific problems, which more often than not do not fit into the classic case interview frameworks (or can be derived from industry drivers and trends) that were en vogue 10 years ago...

Again, this only applies if everything you say

• adds value to the problem analysis
• is MECE
• is well qualified
• includes a detailed discussion of your hypotheses at the end

As a result, you can spend several minutes, guiding the interviewer through your structure!

Now for Structure and Exhibit Interpretation, there is also no right or wrong answer. Some answers are better than others because they are

• deep
• broad
• insightful
• hypothesis-driven
• follow a strong communication (MECE, top-down, signposted)

That being said, there is no 100% that you can reach or the one-and-only solution/answer. It is important that your answers display the characteristics specified above and are supported well with arguments.

As for Math questions, usually, there are answers which are correct (not always 100% the same since some candidates simplify or round differently - which is ok), and others that are wrong, either due to the

• calculation approach
• calculation itself

The difference in format and way of answering a question is the reason why I recommend preparing very differently for McK interviews vs. other consultancies.

Now that you know about

• the different format
• the different question types and case briefs
• the ways to answer the questions

you can start using the cases you already have and approach them in a McKinsey-specific way. 

If you have more questions, please feel free to reach out for some free guidance on how to come up with your own McKinsey-type cases on the spot.

Also, check out this answer I wrote on how the cases McKinsey posts online are comparable to the actual interviews: https://www.preplounge.com/en/consulting-forum/are-mckinsey-website-practice-cases-representative-for-what-will-come-10002

If you want to learn more about the McKinsey interviews, have a look at the articles I wrote for PrepLounge:

How to approach the McKinsey Case Interview

How to master the McKinsey Personal Experience Interview

Cheers,

Florian

Hi there, 

That's about right, but interviews usually take longer - 1h, perhaps even more if the consultant is willing to extend it. 

They communicate it as shorter to manage your expectations and to make it easier to timebox it to 1h. 

Best,

Cristian

Typically, you can expect your PEI to run for about 15 minutes. It rarely goes over the 15-minute mark, and even if you're waffling in the last portion of it, expect the interviewer to politely cut you off and ask to proceed to the case.

25 - 35 minutes for the case portion is fairly standard, so all in all, your assumptions are in the ballpark. I would disagree with you that a ‘standard case’ takes ‘45 minutes or so’ as there are some unique variables at play during the case interview and especially with the McKinsey format.

I - practice sessions tend to be looser for time than actual interview cases. In your practices, your partner is solving for meeting the your learning objectives which usually takes a bit more time. You can expect that the trained interviewers have tightened their cases and perfected their prompts to ensure they can deliver their cases in a shorter time-frame than what you are used to.

II - the McKinsey format is loosely time-bound based on the questions you will be answering. In this format, the interviewer is firmly in the driver's seat and has even greater control of time than the other formats. As you progress through the case: i) design and explain your issue tree, prioritisation order, and initial hypothesis; ii) analyse your first exhibit, extract key insights, and feed those back into strengthening/revising your hypothesis and advancing towards the objective; etc., etc., the interviewer is guiding you through the distinct sections with a keen eye on time.

In my time, NONE of my case interviews in the first round ran over the 30-minute mark, and this time factor seems little changed since then. 
(Yes, I timed all my first-round MBB interviews!)  :-)

I wouldn't worry that your practice sessions are taking longer than will actually likely happen at your interview.  I would, however, encourage you to be aware of this (as it seems you are) and try a few sessions under more interview-accurate conditions if getting a feel would keep you from ‘psyching’ yourself out.  ;-)

(editiert)

Hi there,

Your assumptions are about right.

You're probably surprised that you only have 20-25 minutes because it's the natural tendency of most fellow candidates to allow far too long on cases! When you're casing with peers, remember that this is not fully representative of the case experience (it's a bit of the blind leading the blind).

Real cases tend to be shorter, more abrupt, move more quickly, and “help” less.

All that said, be careful expecting anything. It could be that your case is 40 minutes or 5 minutes. You might have 1 PEI question or 5.

Yes, there are general rules/tendencies…but make sure you go in ready for whatever happens.

(editiert)

Hello,

Don't worry too much about this. The PEI portion is usually around 15 minutes, the case is about 20-25. The case will have been structured to only take around 20-25 mins: you are not being asked to solve a 45 min standard case in 20 mins, in other words. The interviewer will guide you through all of these portions, and you may go longer on some and quicker on others. There is also some time at the beginning for small talk and at the end to ask questions.

There’s no need to psych yourself out! So each interview is generally 45-50 mins:

- 5 min small talk

- 15 min PEI

- 20 min case (generally 3-4 questions)

- 5 min for you to ask questions

Time can shift between the PEI and case - and if you go long then you may not have time for questions at the end. But this doesn’t mean anything! The interviewer may also take some notes on their laptop while you’re taking time to think through answers on the case - this is just so that we don’t forget what you said!

Emily

Hi there, 

unless you are experienced hire, very likely Personal interview will not take more than 15 min and case will be 30 min. 

Good luck!

Lucie

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