Best Practices for solving case on your own

Case Case Interview case practice Case Prep MBB strategy
New answer on Oct 23, 2020
10 Answers
6.7 k Views
Anonymous B asked on Jul 04, 2018

Hi experts,

Can you recommend good approaches to solving a case on your own? How to maximize the learning experience? How to balance self-solutions with solving a case with a partner...

Overview of answers

  • Upvotes
  • Date ascending
  • Date descending
Best answer
Originally answered question:

Case Prep Newbie: Prepping Solo

Content Creator
replied on Jul 02, 2018
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School


Don't spend too much time prepping solo. Rather practice solo a certain type of a case and then practice them with a partner, Repeat the process multiple times

In terms of resources - Start with Case in point, Victor Chengs books and LOMS.

In terms of case types I would start with either market sizing or with profitability cases since they are much easier:

1) In market sizing cases I would try to understand the basic approach:

  • How to structure market sizing case
  • Key tools (Assumptions, Households, using personal experience, adjustments, age groups, Income split via 80/20, peak / off-peak calculations, replacement rate, using size of the area to calculate markets, calculating adjacent markets, sanity checks, etc).
  • How to do math in the case interview

2) In Profitability cases, I would learn

  • How to ask clarifying questions
  • How to structure profitability cases
  • How to work with data (Comparing with competitors, segmentation, historical data)
  • How to answer the questions on creativity
  • How to provide recommendations

3) Then I will switch to Market context cases (Market Entry, New product, Acquisition, etc). In addition, I would learn how:

  • Structure market context questions
  • How to analyze graphs and tables

4) After that I would look at other case types: Operational math problem (e.g. Should we increase the speed of an elevator or just buy a second one? How should we reduce the queues? Etc.), Cost Cutting, Valuation, Private equity due diligence, Synergies, etc.

Also, I would try to 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

Also, several things that you should be doing on a regular basis:

1) Every 10 cases revisit the previous cases and think how you would structure them differently now having the new experience and having solved the new types of cases

2) Build business judgment. Read about different industries and functions. I strongly recommend practice drawing structures for each industry - profitability, value chain, etc . Then I will switch to getting functional knowledge and key concepts in Marketing (Brand and trade marketing tools, etc), Supply chain (Ops metrics like cycle time and throughput time, distribution and delivery specifics, etc), Finance (Basic Accounting and Valuation). Good sources might be:

  • Books - one good book about airlines with numbers and industry analysis can give you all needed industry knowledge
  • Company reports, equity reports, etc - usually have a good overview of company and industries.One of the best sources to prepare
  • HBS cases - quite useful, but not sure if lot's of them available publically. Probably worth buying

Again, every 10 cases revisit the previous cases and think how you would structure them differently now having the new knowledge

3) Practice fast math

  • Learn how to multiply double digit numbers (google fast math tips)
  • Learn the division table up to 1/11 (i.e. 5/6 = 83.3)
  • Learn how to work with zeros (Hint: 4000000 = 4*10ˆ6)
  • Use math tools (Mimir math for iOS), Math tool on Viktor Cheng website to practice

4) Read Viktor Cheng Book and listen to LOMS. I recommend to reread the book and listen to LOMS every 15 cases. Every time, having more experience, you’ll be finding something new.


Was this answer helpful?
Originally answered question:

Alternative Case Prep Strategies

replied on Jul 14, 2018
Ex-McKinsey Consultant; received offers from McK, BCG, and L.E.K.

Dear [],

I'm sorry you're having difficulty finding good partners,

Most of the things you mentioned in your questions are great strategies to getting some good quality prep in. In my time, I found that the alternative prep methods that added the most value for me were:

+ Listening to/watching case recordings online (high quality case content and delivery, of course!)

+ Self-practice when I wanted to hone specific areas (i.e., solo practising the communication a top-down, hypothesis-driven structure at the start of the case in a precise and concise manner)

I did not do the rest of the things you mentioned. I cannot imagine that reading business press is the most effective use of your time, and I would strongly caution AGAINST reading 2-3 Cases a day.

The single best form of interview prep you will ever derive is Case Practice with a skilled partner. You should solve for that. Unfortunately, once a Case is read passively, it can never again be considered an effective prep resource. Since the number of high quality Cases out there is in very short supply, if you read the best ones passively, you may find yourself in a bit of a quandry once you start to ramp up. There will be no good material left!

So, what can you do in the meantime?

3 things:

1. Keep watching videos of well-simulated Case cracks.

2. Look out for print resources that help you simplify and better understand how Case cracking is achieved for high-performing candidates. Victor Cheng's suite was a tremendously helpful starting point for me.

3. Don't give up on good partners. Look for great partners right here on Prep Lounge. Once you find the few really good ones, keep them and keep practising with them!

Happy to help with any further questions you may have on this! :-)

Was this answer helpful?
Content Creator
replied on Jul 04, 2018
#1 Coach for Sessions (4.000+) | 1.500+ 5-Star Reviews | Proven Success (➡ | Ex BCG | 9Y+ Coaching

Hi Anonymous,

the following should be a good mix of self and peers preparation:

  1. Read Case In Point or Case Interview Secrets for a general understanding of what a consulting interview is. Don’t focus too much on the structures proposed in the books though, as they are not good enough nowadays
  2. Start to read MBA Consulting Handbook – you can find several for free online (Insead is a good one to start). Read the cases and try to apply your structure. Whenever you see there is something missing, upgrade your structure with the new insides. Try to read at least a new case per day – in this way you will absorb a lot better the information with constant learning
  3. After having read the first 10 cases in books/handbooks and basic theory, start to practice live. There is a relevant part of the interview score that is based on your communication, which you cannot practice at all if you read cases only. Keep track of your mistakes and see if you repeat them. If so, try to identify the source of the mistake (feedback of experienced partners would be particular useful for this)
  4. Once you feel you are not improving anymore, if you have a tight time constraint or if you want a realistic assessment of your level, consider using experts’ support to strengthen your performance



Was this answer helpful?
Originally answered question:

Alternative Case Prep Strategies

replied on Jul 14, 2018
Ex-Oliver Wyman with 100% interview success rate - specialized in female career coaching


sometimes it may indeed be a bit difficult to find good partners to practice with. However, as my colleagues here already said: There is no way around practicing cases with skilled partners.

What I recommend:

  1. Do cases with as many different partners as possible until you find a skilled and experienced one. Once, you found such a partner, it makes sense to arrange further meetings with this person specifically. If you prepare over a longer time period, you will probably need more than one of those good partners. When I was preparing for interviews, I usually had 2-3 partners, I regularly practiced with.
  2. Depending on your availability, it makes sense to do at least 1 meeting per day (where you are both in the position of interviewer and interviewee) and, if necessary, more than 1 in the weekends.
  3. If you are very limited in the time you may invest in your interview preparations, think about doing a coaching session with a former consultant. This is usually the most effective and efficient way to prepare for interviews, once you know the basics.
  4. Even if you are likely to think there is no point in practicing with less experienced partners, there is an important value to it: You will notice the mistakes that person makes while solving the case. Most people underestimate the learnings from this, however, this will teach you frequent mistakes that you should avoid whenever you are the interviewee.
  5. Aside from practing with other candidates, it is indeed very valuable to read the business section in the wsj and to practice maths. However, this alone will not get you any job offers! The most important part is to practice cases in a live situation.



Was this answer helpful?
Patricio replied on Jul 08, 2018
Current McKinsey Associate

Hi Anonimous,

I think Francesco and Vlad have covered all the best practices that are out there. I will only add a method that personally helped me while I had to prep solo (I tried to solve 2-3 cases per day and sometimes it was difficult to be free at the same time).

I call this simulation. I just grab a case I haven't solved and read the problem statement. From there, first I imagine what are the initial questions that I should ask (this was one of my weak points). Then, I play both interviewer and interviewee role and keep developing the case until coming to a solution. Lastly, I give myself 30 secs to come up with the summary and recommendations. I do this out loud (I even speak my thoughts out loud), so I would advise not to do this in a public place (people will think you are crazy).

This by no means replaces practicing and solving cases with other people, but I believe it helps to train your mind in using the case solving process.

Good luck with your interviews. All the best,


Was this answer helpful?
Content Creator
replied on Oct 23, 2020
Ex-Mckinsey|Certified Career Coach |Placed 500+ candidates at MBB & other consultancies

The best way on how to maximize your learning experience is to start your practice with peers, or (the most efficient way) with a professional coach. Thus you can recieve structured feedback after each practice, and know on how and where to improve.

Hope it helps,


Was this answer helpful?
Anonymous replied on Aug 25, 2020

Dear A,

I would recommend you not to stuck in a phase of a solo preparation and find a peers or a coach as soon as possible.

You will immediately notice the huge difference in your preparations and progress as well.

PrepLounge gives enough opportyunities to make it happen for you.

Wish you all the best,

If you need any further help or advice, feel free to reach out.


Was this answer helpful?
Vlad gave the best answer


Content Creator
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Q&A Upvotes
186 Reviews