Hi there,

I like how you have broken down the process. I also like how Paul has pointed out how important it is to clarify the question so that you are sure about what you are solving for.

This is basically a market sizing, so all the same market sizing rules apply here!

The most important one for you right now? Leverage what you know about the world to estimate, not guess. Break down the problem into segments that allow you to estimate based on what you know already.

Hi there,

I think this is an interesting question that may be relevant for many people. I would be happy to share my thoughts on it:

• First of all, while this type of brain teaser/mini case might still occur with smaller strategy consulting companies, it is generally very rare and will not happen with any bigger strategy consulting company for the simple reason that they are very limited with regards to the skills and the scope of how these skills are being tested.
• Moreover, I like your approach, and most likely, I would have approached it the same way by analyzing the value chain and identifying the amount of water required for each "product" created at each step. Unfortunately, the value chain and some details are all that can be provided for the structure (once again, it highlights that the scope of skills being tested is limited).

If you would like a more detailed discussion on how to address your specific situation, please don't hesitate to contact me directly.

Best,

Hagen

You are on the right track. Basically define the process. Then you have to consider IF and WHY you need water in that process step. Then how much you need.

Usually you will need significant ammount of water to grow the beans and to make the coffee.

What are you missing? 

- First you are not closing the loop, i.e., the process does not stop when the cup is served (you need to wash the cup later on… or if you prefer, before you pour the coffee).

- Second there are a lot of associated processes / goods (cleaning the coffee shop, water in energy production, etc. etc). Although I feel one could fall into a rabit's hole going down this path. I would just state this and dismiss it.