Brainstorming, MECE & 80/20 principles case interview video

You are unlikely to pass a McKinsey, BCG, Roland Berger or Bain case unless you can brainstorm. Although, you may never receive an isolated/explicit brainstorming request in a case, the skill is needed to identify drivers and build out an analyses structure.

Why is this important?

Candidates who can brainstorm well will never need to memorize a case framework for the rest of their lives, or get stuck in a case when they cannot recall a framework. No matter how many frameworks they memorize there is bound to be a case which requires a type of analyses they have never seen before, and if they cannot brainstorm, they cannot develop the required analyses approach. Moreover, comfort with this technique plays a major role with confidence building since the candidate never needs to worry about facing a case without a bag full of frameworks. They will not need them.

Firmsconsulting does not teach frameworks. There are no high-five’s for using the correct framework. We encourage candidates to learn to solve cases from first principles and if a framework is ever used, we spend an inordinate amount of time testing their understanding of the approach. This understanding and candidates ability to explain their reasons for using the approach, are far more important than the approach itself. In a simple test, we get candidates to introduce the 4P’s framework to us. Rarely does that go well.

Too many students are obsessed with memorizing frameworks to get offers. Too many online resources present frameworks as the only way to go ahead. Candidates must realize that about 70%-90% of all McKinsey et al hires will be managed out within 2 years of joining. Every time you see consulting alum that left without a promotion from analyst or associate; you should ask yourself if they were managed out aka asked-to-leave-for-poor-performance.

We encourage our clients not to be someone who just does enough to get an offer. You really want to learn the correct approaches so that you can succeed after you join, and never get managed out. So do not just do enough to get the offer, use the effort expended preparing for consulting interviews to learn the correct techniques. That means brainstorming, decision trees and hypotheses development must be studied carefully.

We find that candidates generally brainstorm in a very haphazard way. Most simply throw out ideas/solutions which they think best solve the problem they are brainstorming. For example, if we asked a candidate to brainstorm what are the main variables costs at a banking division offering corporate loans, they would likely do the following.

• They would focus on the variable cost part and simply throw out all variable costs they can think of.
• Thereafter comes the painful part of seeing them try to force-fit these ideas onto the question.
• Blurting out solutions is right-brain thinking.
• Moreover most candidates forget to apply MECE rules and 80/20 principles.
• It is the incorrect to brainstorm this way.

The correct way to tackle this case is;

• First understand that variable cost is defined as those costs which directly increase as the volume of service/product produced increases.
• In this case, this is the number of loans.
• The candidate must then consider which variable costs are likely to increase as loan volumes increase.
• Part of the sales force may need increase to go out and sell more loans.
• The back-office will need to increase to process more loans.
• And it is possible the IT and compliance systems costs may go up to manage more loans.
• Apply MECE rules to ensure the list is complete
• Of the three areas likely to increase in size, they must be prioritized for importance and the most important driver must be analyzed further.

In this video we take these steps and explain the rationale behind them, to produce a simple technique a candidate can use to brainstorm. Moreover, candidates usually need to brainstorm in real-time without the luxury of first writing down their thinking. The language used and technique to present the brainstorming is incredibly important. There is no point having the right solution if it cannot be communicated well.

To correctly brainstorm, you need to build a decision tree. If you cannot build a decision tree, you cannot brainstorm, and if you cannot identify the drivers of an issue, you cannot build a decision tree. So it all starts with drivers. We teach 4 types of decision trees, and therefore, 4 ways to build out drivers, and afterwards 4 important steps to quickly and effectively brainstorm. Sounds easy, but it is not.

The challenge, across all candidates, is to force them to move away from ingrained habits of finding a structure and force fitting it to the brainstorming session. That takes a lot of effort since most people do right-to-left thinking naturally versus left-to-right thinking. Both are important, since one is good for hypotheses, but the other is good for decision trees. A candidate must do both well and, as we show in a previous video, you can build better hypotheses using left-to-right thinking, a little trick we will teach our candidates.

This video about brainstorming is only available to our case candidates and can be found in session four of our online case solution video library.

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