No, you don't need 3. Though research does show that groups of 3 are more convincing than 4. 

What you want to do is show you have structured the problem and thought about the important aspects. This can come in 2 buckets with subbuckets or 4. 

There is no need to force yourself to have 3+ buckets. There are cases where 2 buckets for first layer of issue tree make perfect sense. E.g., 

• Profitability: 1) Revenues, 2) Costs
• Costs: 1) Fixed costs, 2) Variable costs 

You should further break this down into additional sub-buckets of course.

Generally speaking, most cases would have more than 2 buckets in the first layer of a “good” issue tree. But by no means, should you “force” this if it doesn't make sense to have more than 2 buckets

Hi there,

2 is perfectly fine! As long as they are MECE and logical AND you break down each into sub-buckets.

Of course, when I say 2 works, that doesn't mean you can do “Financial” and “Non-Financial”. This is “lazy”. If you can have 2 reasonable buckets however that are well thought-out and fit the case, absolutely go for it!

Hi!

It is not true!

It is important, though, that the buckets are MECE and that you can give a solid, well-communicated answer to the brainstorming question.

Hope this helps.

Best,

Anto

There's no ‘right’ way of doing it. 

And definitely you don't need a fixed, ‘x’, number of buckets.

You need to take time and then provide a structure, insightful and creative answer. 

Here's a resource I put together on structuring techniques that you might find helpful:

• Expert Guide: Mastering Structuring & Brainstorming

Best,

Cristian

Hi there,

It totally depends on the question.

If you are analyzing costs and you divide them into fixed and variable, that’s two top-level buckets. However that’s MECE and it is totally fine as an initial division. 

There is no obligation to always have 3+ buckets (which in the above example would be impossible using that division).

Best,

Francesco

Before we move into the actual answer - here is some observation from real world cases. 3 buckets are very cinematically charming while explaining. Its much more effective to drill something into client's heads when it is across 3 buckets. 2 buckets and they feel you have not done a good job. 4 buckets and they lose track. 3 is the sweet spot.

That said - in reality, in the pressure of a case interview - even 2 buckets are fine. UNLESS they are trivial buckets such as financial vs non-financial parameters. Better to break down the non-financial bucket into some other constituents such as strategic, operational, regulatory etc. etc.

Eventually, the purpose of the bucketing in a case interview is not just to create a logical structure that breaks down the case - but it also serves to communicate to the interviewer that you are thinking with a broader mindset.

(editiert)

Hello,

Completely agree here, there is no right or wrong number of buckets. Generally speaking, in most cases you would want to have at least 3 or 4 buckets at the top level, but it is perfectly fine to have 2 top level buckets if it makes sense in the case (e.g. increase profitability → 1. Increase revenues ; 2. Increase costs). As long as the buckets make sense and are MECE, you should be fine.

Consultants love number 3. :)

But they love even more structures that are simple, MECE, and adequate for the specific problem at hand. So the goal is not to reach a specific number, but to solve a specific problem. 

Having said that, 2 to 4 is fine.

Hey there,

Depends on the context and case. For McKinsey, it is a balance between top-level and lower-level ideas.

You can generate excellent frameworks with just two top-levels as long as on the lower levels you expand the depth with insightful and concrete ideas.

If you want to know more about the McKinsey frameworks, have a look at this article I wrote: https://www.preplounge.com/en/mckinsey-interview

Cheers,

Florian