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Market Sizing (Case interview)

I have been practicing the replacement theory but also wanted to reach out and ask if anyone had any additional tips or guidance on this subject as I prepare?

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Top answer
Pedro
Coach
on Feb 26, 2022
Bain | EY-Parthenon | Senior Coach | Principal | Recruiting Team Leader

On market sizing, or on the replacement theory? 

The “replacement theory” is just a small tool within market sizing (and honestly I don't find it intuitive at all).

If it is about market sizing here you have a couple of useful links:
https://www.preplounge.com/en/consulting-forum/market-sizing-approach-12396

https://www.preplounge.com/en/consulting-forum/how-do-you-estimate-the-1-year-annual-sale-of-a-small-corner-coffee-shop-12123

https://www.preplounge.com/en/management-consulting-cases/brain-teaser/intermediate/taxis-in-manhattan-market-sizing-229

on Feb 26, 2022
Pedro,

Thank you for your comment. Apologies for not clarifying my question, but I was referring to market sizing overall. As you mentioned, "replacement theory" is a tool within market sizing.

Thank you for the links. Very helpful.
Ian
Coach
on Feb 26, 2022
Top US BCG / MBB Coach - 5,000 sessions |Tech, Platinion, Big 4 | 9/9 personal interviews passed | 95% candidate success

Hi Jay,

By replacement theory do you mean when you think about the lifespan of a product?

Quite simply, you just need to figure out how many years that item lasts, then divide by that to get the annual replacement.

You can do this for cars, appliances, bed, etc. and you can also do it for “human” factors such as for marriages, illnesses, etc.

on Feb 26, 2022
Ian, thank you for your response. It was about market sizing overall, as well as using replacement theory within the structure of market sizing.
Moritz
Coach
on Feb 26, 2022
ex-McKinsey EM & Interviewer | 7/8 offer rate for 4+ sessions | High impact sessions + FREE materials & exercises

Hey there,

Don’t overcomplicate things!

First time I hear about this theory - same as some other seasoned ex-consultants it seems.

This alone tells me that you might not want to use it in a case, unless it’s really intuitive and easy to understand and, most importantly, appropriate for the problem at hand.

I recommend focusing your energy on developing great custom approaches yourself through fit for purpose MECE frameworks. If you master this key skill, you’re nearly there.

Let me know if this is something you‘re interested in discussing. Best of luck!

Clara
Coach
on Mar 01, 2022
McKinsey | Awarded professor at Master in Management @ IE | MBA at MIT |+180 students coached | Integrated FIT Guide aut

Hello!

Happy that you ask!  Given that market sizing cases were the topic of many questions in this Forum, I developped a market sizing case, that you can find for free in PrepL´s library

https://www.preplounge.com/en/management-consulting-cases/candidate-led-usual-style/intermediate/market-sizing-new-startup-launch-baby-strollers-in-the-us-244

Let me know if you have any doubts with it, it contains a detailed explanation and methodology about how to solve this specific example, but you can extrapolate to many other market sizings!

on Mar 02, 2022
Hi Clara,

Thank you for your feedback. It is greatly appreciated, as I will follow the link that you provided.