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PEI scenario

Case Interview McKinsey PEI Personal Fit Personalfit
New answer on Jul 24, 2020
4 Answers
3.9 k Views
asked on Oct 01, 2017
Actively preparing for my first round McKinsey interviews.

Hi everyone,

This is me just throwing this out and hoping it comes back with feedback. I stumbled on a potential fit question I struggled with at a practise interview and have typed it up as I practised it again to see if the structure and content made more sense.

Can anyone give me feedback on the flow and strength of the scenario as a potential answer?

Question: Tell me about a time when noone agreed with you on something and how you went about it?



Situation: As a medical writer, part of my job was to adapt old jobs to create new ones or evaluate information from old jobs to have an idea of how to create new ones. So earlier this year in April, at HiCare where I currently work as a medical writer, I had to prepare a presentation for the team based on previous jobs that we had done for one of our Pharma clients. The presentation involved using lots of previously approved jobs that I needed to pull from the server.

However, going into our network on the server, I noticed that the same job was being saved in more than one place and was being labelled differently depending on whose folder it was in. In some cases, we had up to 5 versions of the SAME job!. It took me up to 4 hours to both search for info on the server and complete my presentation as opposed to a potential 10 minutes pulling out info and 2 hours on the presentation.

I initially suggested to my account manager and my boss that we change the system but they simply disagreed and claimed it would confuse everyone because they were used to their way of working.

Task: Based on this, I brainstormed a more efficient way of saving/filing jobs and decided I would present it to the team rather than just tell them about it.

Action: I created a 15-minute presentation to explain to the team how my suggested filing system would benefit the company in the short and long term. I elaborated on 3 ways this system would benefit the business and the team:

  • Saves time: By making job searches quicker and freeing up more time for actual work
  • Potentially raise revenues: Free time means more hours in the day to do more billable work
  • Increase efficiency: By simply streamlining a search process makes life easier for everyone irrespective of their position in the company. No need to ask someone to email u a job. You just go into their folder and find the job.

I took them through slides to explain the process and gave them a worked example of how I was already filing my jobs.

Result: When they saw how easy it was they all asked questions (e.g. Q: How to email certain documents to people? A: You simply copy and paste the path in an email) which I answered. Moving forward, my boss bought into the idea. The rest of the team was initially reluctant on adopting the idea but as soon as each person saw how straighforward the process was they gradually started implementing the idea. Now the entire agency uses it.


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Odeh replied on Oct 03, 2017

I personally think (for what its worth) that you have the opportunity to strength your answer using the same example (despite it being more akin to disagreeing with your boss rather than your team).

  1. The context is a bit too long. You need to be brief and to the point. This will give you more time to speak about what you did.
  2. Speak about the brain storming session. Did you sit in a dark room for 3 straight days or did you enage with other team members? How did you ellicit their grievances? How did you arrive to the final solution?
  3. During the presenation, how where you challenged by your boss/colleagues? What did you say to address their concerns?
  4. With respect to the result, was the solution adopted? How did it influence future work? Did you take on other projects/responsibilities since? How did your boss' view of you change since introducing this new process?

Again, this is merely an opinion. I hope it offers you some help and possibly some starting points to begin thinking from.

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Content Creator
replied on Oct 31, 2017
#1 Coach for Sessions (4.500+) | 1.500+ 5-Star Reviews | Proven Success (➡ | Ex BCG | 10Y+ Coaching

Hi Moji,

I think your STAR structure is overall ok; as mentioned by Odeh, you could shorten it a bit, provide more details of the challenges/situation and the effective results obtained. I would actually change the story though: the whole example isn’t impressing. Yes, you manage to make a search process more efficient, but that doesn’t sound an outstanding achievement.

I recommend identifying stories where you led to great results – or had to face great challenges –and use those stories. Remember, interviewers make the same question all the time, and will remember you only if you come out with a story that would differentiate you from anyone else in terms of peculiarity and/or final result.



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Anonymous replied on Jul 24, 2020

Hi Moji,

Your answer shouldn't be soo long. I would recommend for that following the STAR structure:

1. Start with a 1 sentence summary of your background

2. Bring out some problem

3. Talk about 3-4 of your roles (may be professional, education,
extracurricular), 3 sentences each.

4. Shortly explain how did you resolve that

5. Your learnings


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Content Creator
replied on May 31, 2020
McKinsey | Awarded professor at Master in Management @ IE | MBA at MIT |+180 students coached | Integrated FIT Guide aut


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