Hello,

I agree with Francesco on the reasons why you may have sound too structured. It is better to create a framework that will be well adapted to the case, than "blindly" follow a standard framework.

Regarding the "too accurate maths", you should keep in mind that interview cases don't use real/precise numbers. You need to compute are orders of magnitude, not precise results. The result of you computation should have approximately the same level of accuracy than the figures given by you interviewer. For instance, if your interviewer tells you that the company's benefit is about 10.5 million€ and ask you how much the new initiative you've been discussing will increase the benefit. Your answer should be in million with a single digit (e.g. 1.7 million€). Don't answer 1 689 234 €. You will loose time computing such a precise answer and you know for sure that the "89 234" is not a relevant piece of information.

They want to know whether you can do "back of the envelop" thinking :

• Can you figure out quickly what is the good way/good model to compute an insightful result ?
• Are you at ease with numbers ?
• Are you able to have a critical eye on your results ?

Indeed, while working at MBBs, you will do a lot of big Excel models with plenty of numbers. It is easy to make errors ( e.g. selecting the wrong cell with a fat finger...). MBBs expect you to realize, on your own, when something went wrong in your model. For instance, with a "back of the envelop" reasoning, you know that the result should be around 10. Your Excel model would tell you whether it is 9.51 or 10.8. But if you find 30 ou 200, you should see on your own that something went wrong.

Hope this help!

Good luck for the rest of your interviews!

I had a case interview preparation with an experienced consultant and he told me that for McK case solving, my structure should be more framed. In that sense the feedback of McK was confusing. I guess my case was indeed perceived too structured and I will work on that. Thanks for your answering.

(editiert)