What to Include in Issue Tree

issue tree
Recent activity on Oct 09, 2018
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Anonymous A asked on Oct 08, 2018


Sometimes you get a feeling about what the core areas of a case is. Then, I sometimes draw up an issue tree. Should this issue tree include elements that I consider not very relevant to the case just to make sure that it is as MECE as possible or is it more important that every element included is super relevant? I just feel that sometimes there aren't enough elements that are relevant to make a MECE tree without adding elements that are sligtly unrelevant. Any tips as to how to solve this issue?

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replied on Oct 08, 2018
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School


First of all - not all issue trees can and should be MECE. Very often it's not the case.

Secondly - there is a number of ways how you can approach in a MECE way:

  1. If your structure works mathematically (e.g. Total time spent on cleaning operation = # of people x Frequency x Hours per cleaning per person)
  2. If your structure comes from a formula (e.g. output rate = total number of people being served / time to serve one person)
  3. If you are using the common industry drivers (e.g. revenues = # of customers x av. check) (e.g Passengers on the plane = capacity x Load Factor) or theindustry revenue streams (Fuel revenues / non-fuel revenues for the gas station) or the functional drivers (e.g. for the problems in sales : Sales strategy / sales people and allocation / motivation / sales process)
  4. If your issue tree is a real framework used by the consultants (e.g. the famous Bain Cap framework for PE due dills: Market / Competitors / Company / Feasibility of exit) (e.g. People / Process / Technology) (e.g. The famous McKinsey framework - People don't want to do smth / they can't do smth / smth prevents them from doing that)
  5. If your structure is a well-known academically MECE framework (e.g. Product / Distribution / Price / Marketing (Also known as 4P))

There is no magic pill how you can learn to build the MECE issue trees. !!!! It comes with a lot of Practice and reflection and building proper industry and functional knowledge. !!!!

Focus on the most common industries in the following priority (sorted by probability of getting a case): 1-retail and CPG; 2-airlines; 3-Telecom; 4-banking; 5-natural resources; 6-tech

There are several sources of information that will help you develop the business sense:

1) Cases - you simply solve 50-70 cases and get a broad knowledge of different industries, common pitfalls and questions. The key here - find good partners who already had case interviews with MBB companies

2) Company reports, equity reports, IB roadshow docs - usually have a good overview of company and industries.

3) HBS cases - quite useful, but not sure if lot's of them available publically. Probably worth buying

4) Industry Books - one good book about airlines with numbers and industry analysis can give you all needed industry knowledge

5) News, Industry blogs

For each industry, you should understand:

  • Revenue streams
  • Cost structure
  • Margins
  • Key performance indicators
  • Key revenue drivers
  • Industry trends

I strongly recommend drawing the typical structures for each industry - profitability, value chain, etc

Then I will switch to getting functional knowledge:

  • Marketing (Brand and trade marketing tools, etc)
  • Supply chain (Ops metrics like cycle time and throughput time, distribution and delivery specifics, etc)
  • Operations (Process optimization basics)
  • Finance (Very basic Finance and Valuation)

Good Luck

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Anonymous replied on Oct 08, 2018

While it is important to be MECE and exhaustive, it is also important to demonstrate you are 80/20 and able to focus on what's most important. Therefore, the structure should focus on what the key, important buckets are. Within these, if you have an initial hypothesis (maybe based on the industry, or based on what the case prompt is) that one is more important than the other, you can order and prioritise accordingly. The rule of thumb is, "if the answer to this question/bucket could change my answer significantly, it should be included in your issue tree". Ifyou hypothesize that the answer won't change the answer, then you should still include it, but can prioritise elements you think will be more important (but be ready to be proven wrong based on the information in the case.)

Let me give you an example - in the case of a Merger, besides potential Revenue and Cost synergies, culture is an important aspect to include and consider. However, if the case is a merger between two German companies, you might hypothesize that the cultural difference won't be huge, so could put it at the end of your structure and not dedicate as much time to it.

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replied on Oct 08, 2018
Ex-MBB, Experienced Hire; I will teach you not only the how, but also the why of case interviews

The framework does have to be MECE, yes - no way around this one. If however you have a very strong sense of what the issue is, you absolutely can put this near the beginning. Be careful though, many cases are tricky (mine are for example), and what may initially look like a promising hypothesis will more often than not just end up be a dead end.

PS: Just like when you have an epsilon in a math or physics formula, the "all others" bucket can be a life saver - use sparringly, but it is an option

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replied on Oct 09, 2018
ex-Manager - Natural and challenging teacher - Taylor case solving, no framework

Structure should ALWAYS be tailored to he the case you receive. As I keep saying here a unique client issue require a unique approach.
So I will definitely recommand to prioritize and focus on the topics you think are the most relevant and de-prioritize / drop others. In case you have a doubt you can put it in last position, with emphase saying that depending on the previous findings we might or not consider this last topics.
Hope this helps

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Vlad gave the best answer


McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
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