Looking for examples of a public sector case interview? You’re in luck. In this McKinsey-style public sector case interview, a candidate takes on the tough task of helping a city public school system improve the academic performance of its students. It’s a case that requires creativity, critical thinking, and problem-solving skills. See how our candidate did in the video below.
Follow along:
- Case prompt (1:20)
- Framework by interviewee (6:50)
- Brainstorming question (23:50)
- Final recommendation (33:31)
- Feedback by interviewer (34:50)
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Transcription: Public Sector Case Interview
MC
Let’s go ahead and dive into our case for today. So, this case reflects a little bit of my background actually in the education space. It may not be a space that you’re really familiar with, but I’m excited to dive in and see what thoughts you may have. So let me tell you a little bit about the client set up here.
Your client is going to be a public school system in the US. Now they’ve got 130,000 students in total, multiple locations across one city area. The average score of the students in a statewide exam is much lower than the scores of students from the rest of the state. And so they brought us in to try and help. The clients pose the key question of, how would we improve the academic performance of the students in the city? In this public school system, there’s 13 grades or levels. It’s broken into three main groups. There’s the elementary schools, which range from kindergarten to sixth grade. There’s the Junior High School, which is seventh and eighth grade. And then high school is ninth through 12th grade.
Candidate: Marco
Okay, so I just took notes of everything. Let me recap the prompt. So our client is a public school system that is based in the US, we’re talking about multiple locations of schools in an American city, which has 130,000 students. What the client is asking us is how can we improve the academic score of these students because their academic score is actually lower than the average scores that was recorded in other locations in the US. So my first question is, first off, do we have any specific objective of the client? So is he just trying to ask us ways to improve? So brainstorm and new ways to improve it?
MC
Well, they want to see their academic performance scores for their school system increase.
Candidate: Marco
Okay, sure. Do we have a specific grade, or specific average or academic score we’re trying to achieve? And if so, in how long? What is the timeframe they’re trying to achieve that?
MC
So there’s no specific target, I’m sure that they want to get at least parity to hit the average. I’m sure that they’d like to do above average as well. They’d like to be able to hit this as soon as possible but they’re looking to our guidance for that as well, in terms of timing and implementation.
Candidate: Marco
Okay, sure. So I just want to better understand our clients. So is it like a big school that has other schools, that then make the 130,000 students?
MC
Yes. It’s like a collection of schools is what would be the public school system. So there’s going to be multiple elementaries, junior highs, high schools.
Candidate: Marco
Okay. Got it. Okay, great. So I’m just gonna take a minute to gather my thoughts and think about some ways to improve the academic score.
MC
Actually, before you do that, let me have you answer one additional quick question here, which is, do you have any ideas about what you think maybe that the KPIs would be or the metrics that matter in terms of improving academic performance?
Candidate: Marco
Well, for sure. Actually, I don’t have great experience with that. But I can think of it as the knowledge of the courses kids are taking in school. So if they improve their knowledge of specific courses, for example, math, they’re gonna do better in taking tests and improving their score.
MC
Yeah, I think that’s some really good intuition. Absolutely. A lot of this is based on standardized test scores, and how well the students at each grade level do on how well they score on those standardized tests. So nice job. Okay. So go ahead and feel free to put a plan together here.
Candidate: Marco
Okay, sure.
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Candidate: Marco
Okay, good. So the way I would address this issue to improve academic scores is make the assumption that in order to improve it, kids or people in these 13 grades should better understand or learn the courses they take. So to do that, I structured the way I want to solve the problem into buckets. What we could do in school, and what we could offer outside school. So what we could do in school is increase the number of hours students stay learning or diversify the work. So, introduce new way of teaching, for example, group projects. Finally, do some more interactive teaching.
Outside school, we could do recorded lessons. So again, I’m thinking about recording the courses and make the students re-watch the classes they took, but do it at home. Or also, the school system could partner with companies that develop specific courses that can broaden the knowledge of kids outside what is taught in class.
MC
Okay, where would you start?
Candidate: Marco
So I think I would start from what is done in school. So understand what actually is done now and what we can improve by looking at what the school system has already implemented.
MC
Great. Okay. So we have found one area so far of potential improvement. I want to tell you a little bit about it.
Something that’s going on right now is students are not getting their books on time. So here’s some background information that we know. We know that there’s the same number of students in each grade within the school system. And let’s assume equal number of students in each grade, equal number of students in each class.
For mathematics, each student is going to order two math books. Today, only 75% of the books arrive on time. In current state, this inefficiency is determined to be 75% due to warehousing, and 25% due to online orders. McKinsey, we’ve already started a little bit of work in this area, we’ve created some improvement suggestions, and if the client follows through with those, a new warehouse model would improve the efficiency by 50% and online orders would be improved by 80%.
So, how many additional math books should the junior high schools get on time with the improved efficiency in the system?
Candidate: Marco
Okay, sure. Let me just finish writing. Okay, let me recap what I just wrote down. So first off, the problem McKinsey identified is that books are not delivered on time. The first assumption is we have the same number of students in each grade and class. Then each student orders two books, and 75% of those books order arrive on time. Then we have a 75% of these books are stored in the warehouse and 25% come from online orders.
MC
So the 75% and the 25%, that helps denote what’s going wrong when the books don’t come on time. Those are the inefficiency areas.
Candidate: Marco
Okay. Sure. So what does the 75% really mean? So 75% of the books that don’t arrive on time go to the warehouse?
MC
75% of the books that don’t arrive on time are late because of warehouse issues.
Candidate: Marco
Okay! So the problem is 75% on the warehouse and 25% to blame on the online orders.
MC
Exactly.
Candidate: Marco
Okay, got it. Now we’re thinking about new warehouse improvements which would improve the warehousing by 15% and 80% the online orders.
MC
Yeah, the warehouse improvements would improve that area of inefficiency by 50%, five zero.
Candidate: Marco
Okay. And what about the 80?
MC
Yep, and online order inefficiencies would be improved by 80%.
Candidate: Marco
Okay, thank you for the clarification. So now the big question is, how many books? Can I hear that again, please?
MC
Yeah. How many additional math books would the junior high schools get on time with the improved efficiencies in the system?
Candidate: Marco
Okay, now I understand. Junior High School. Okay, good. So, what I will do now is understand how many kids are in junior high school, so seventh and eighth grade, then I will calculate the potential number of books that should arrive, understand how much actually arrive on time doing the percentage on the total books, and then improve it by the percentages we talked about before.
MC
Great.
Candidate: Marco
Okay. So, we have 130,000 students and 13 grades, which means that each grade has 10,000 students. Junior High School is just two grades, so seventh and eighth. What I will do now is multiply 10,000 students by two. So we have 20,000 students in grade seventh and eighth, which is Junior High. Are we assuming that 100% of the students order two books?
MC
Yes.
Candidate: Marco
Okay, so we now have 40,000 math books. Out of 40,000, just 75% arrive on time. So I’m just gonna do the percentage on this. 10% is 4,000, which means that 5% is 2,000. So it’s 4,000 times seven plus 2,000. So, 30,000 books arrive on time. So we are missing 10,000 books, but the question now is if we do the improvement, how many more are we getting?
So what I’ll do now is find the percentage, so the 75% that are due to the warehouse on the 30,000 and then improve it by 50% and then calculate the 25% on the 30,000, which is due to online orders and improve it by 80%.
MC
Well, the 75% and the 25%, those speak to the inefficiencies, not the books that they get there on time.
Candidate: Marco
Okay, sure. So, I’m trying to think about inefficiency, right. The inefficiency – 75%? – what exactly does it mean? I’m trying to brainstorm, to speak out loud, but that’s what I’m trying to think about. Okay, so this is due to the inefficiency. Oh, which means 75% of the 10,000 which don’t arrive.
MC
Yes.
Candidate: Marco
Okay, good. Okay, now I will do what I said but with the 10,000 instead of the 30,000. Is it the correct approach to move on?
MC
Perfect. It is.
Candidate: Marco
So let’s calculate 75% of 10,000 which is 7,500 books. And 25%, which is 2,500. This is for online orders. So now I need to improve 7,500 by 50% which is 3,250.
MC
Check that one more time.
Candidate: Marco
Okay. Yeah, it’s 3,750. And then by 80% on the 2,500 which is 250 times eight, because of the 10% now multiplied by eight. So 250 times eight. Okay, so 2,000. Which means that if we were to improve our efficiency, we will get an extra total of 5,750 books.
MC
Say that number one more time? I didn’t catch it.
Candidate: Marco
If we were to do our improvement on efficiency, we would have 5,750 books.
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MC
Okay. What do you think about that?
Candidate: Marco
Well, it’s not enough. It’s still something, but it’s just a little bit more than half of the books were missing. Because we’re missing 10,000 books, and we’re going to get a little bit more than half. So I should definitely be interested in thinking about ways to increase this number.
MC
Okay, great. Now, let me ask you Marco, what role do you think teachers play in all of this?
Candidate: Marco
The role the teachers play, you mean in improving academic scores, right?
MC
Yep.
Candidate: Marco
Well, let me just take 30 seconds to have a more structured answer, but if I just were to start, I would say that I think this public school system, in our case, that tells teachers how long they should teach, and the way they should teach. So I’m not completely familiar with the US school system but maybe teachers have more freedom to decide on the way they want to teach.
So if that’s the case, they can definitely have an impact on the improvement of the academic test scores of students. So if we have any information about the freedom of teachers in teaching kids, that will be helpful.
MC
I would say as basic context here in the United States, teachers are certainly prescribed at an outline level, or maybe at a lesson plan level, but not down to the minute and the format of delivery. It’s not fully prescribed. They do have flexibility and freedom to decide how they want to teach and what information to convey to the students.
Candidate: Marco
For sure. So with this information, I would definitely say teachers do have an important role in kids improving their academic scores.
MC
What are some of the ways that you think that they might be able to improve on this key metric?
Candidate: Marco
Sure. So I’m thinking about three ways. So the first one is the way they teach. So is it just a frontal teaching? Like, I’m just teaching you things, you need to rehearse them and then say it back to me? Or is it a more interactive way of teaching?
Second is what they teach. Are the things that they teach actually tested on those tests, or are those teachers teaching what is not tested on the tests? Third, the how. So is it just in class, or is the teacher giving extra tests or papers to write at home? Is the teacher stressing the fact that students need to keep up with the work? So I’ll say these three drivers.
MC
Okay, awesome. Can you come up with one more?
Candidate: Marco
One more? Yeah, sure. So, are the teachers vouching for just books are also an interactive way of teaching, like watching YouTube videos, because recently school systems are changing. And there is a big part of the internet playing a role in teaching kids. So it really depends on how teachers conduct the way they teach. Is it very book-driven or are other ways of learning considered?
MC
Okay, great. With that, we talked a little bit about the roles of the teacher and how to improve access to on time books. Let’s look at another issue, which is capacity utilization. The school system has decided to move the sixth grade from elementary to junior high school. Currently, each elementary school can hold a maximum of 6,000 students. But today, only 4,800 students are enrolled.
In this question, we should not assume that there is an equal distribution among the grades. Instead, let’s assume 600 students are in the sixth grade. What would be the new capacity utilization by moving sixth graders to junior high and what’s the percent change in capacity utilization?
Candidate: Marco
Okay, great. So I just want to tell you what I wrote. So we’re saying that sixth grade is going to be moved to Junior High. So we’re saying that each school has 6,000 students, correct?
MC
Each Elementary School.
Candidate: Marco
Okay. And now, only a number of those students are enrolled. I missed the number of students enrolled.
MC
So the building can hold up to 6,000 students, but there’s only 4,800 Students enrolled.
Candidate: Marco
Right. And then we’re gonna move 600 students to the Junior tier from sixth grade. Now what we’re trying to understand is the percentage change in capacity utilization. Okay, so what I will do is understand how many schools we have, multiply that by the number of students enrolled? Is the number of students enrolled the sixth grade, or all the grades?
MC
The sixth grade.
Candidate: Marco
Okay. So, multiply the number of enrolled sixth graders by the number of schools.
MC
Well, we can consider that that stays consistent from elementary school to elementary school.
Candidate: Marco
Right. But I’m saying what I would have done is get the additional number of books that these 600 students will need to order.
MC
Capacity utilization for the building is a separate idea than the books that they need.
Candidate: Marco
Okay, I’m sorry, I missed that. So we’re talking about the capacity utilization of the building. Perfect. So, let’s start with some percentages. What is the percentage of students of sixth graders in each school? So it’s 4,800 divided by 6,000.
MC
Yeah, that’s the current utilization.
Candidate: Marco
Right, which is 480 divided by six because I already did the calculation in percentage. So what I did is 4,800 divided by 6,000 times 100. Which gets us to 80%. And this is just one school.
MC
We can consider that’s consistent across all elementary schools.
Candidate: Marco
All the schools have 80% capacity utilized. So now we are adding 600 students from sixth grade to Junior, which means we’re going to have 4,800 plus 600.
MC
Not plus.
Candidate: Marco
So are we adding 600 students in each school or all the schools in total will increase by 600?
MC
Currently, sixth grade is in elementary, but sixth grade is now going to move to junior high.
Candidate: Marco
Right. So the number of students in sixth grade is actually 10,000.
MC
No, for this question, we’re assuming 600 in sixth grade, but they’re going to be removed from the elementary and moved over to Junior High.
Candidate: Marco
Okay, so now the capacity decreases.
MC
Yes.
Candidate: Marco
Okay, now I see. So it’s gonna be 4,200 over 6,000 times 100. Which means 420 over six in percentage, which is 70%. Okay, so the change in capacity is 10%. Okay, good. So, 10% is actually not that high. 80% of the school building was occupied, so now that we decreased by 10% is definitely something to consider. I don’t think it’s a big number, but it’s definitely something to look out for.
MC
What do you think might be some of the implications of that?
Candidate: Marco
If the number of students in school decreases, I will say that the revenue from the school will decrease. So revenue decreases, then classes will be a smaller size. So taking it back to the learning process, I think this actually could improve the academic scores, if we assume more classes learn better. So if less kids are in class, maybe they retain information better because they are not distracted by other colleagues.
And the third implication is the fact that lower capacity would mean that even though we still have the inefficiency, we could actually have better book delivery to students, because less people are in the school. But we’re not gonna order the same amount of books, so the number of books is going to decrease. So kids are going to be more likely to have their books.
MC
Okay. Marco, how would you summarize our findings so far?
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Candidate: Marco
So the first question was, how would we improve the academic score? And we found that we have an inefficiency in delivering books, but McKinsey actually managed to understand how to improve it. And we found out that teachers play a big role in kids increasing their academic score.
With that being said, now, we are thinking to move sixth grade to Junior High, but this will decrease the capacity in the building. So those are the things that I noted now.
MC
Okay. Any other final comments?
Candidate: Marco
No, not that I can think of.
MC
Okay. All right. Break.