Hi I'm Jenny Rae, the Managing Director of Management Consulted, and I'm back
today to continue our series on case interviews. In particular today we're
talking about problem solving. Problem-solving is one of the most
critical things that you need to demonstrate as an interviewee sitting in
the hot seat in a consulting interview. What I'm gonna do today is I'm gonna
break down problem-solving into 4 key areas and how it's demonstrated with
success in the interviews as well as key mistakes that we often see when we're
working with case interview candidates. So without further ado let's get started.
The first thing that is incredibly important to demonstrate when you're
thinking about problem-solving in case interviews is that you are excellent at math.
Now there's a lot of confusion that has come about around the math issue.
First of all, the idea of mental math is a common hang-up. Consulting firms are
not looking for you to do math without writing anything down. When they say
mental math, what they mean is that they want you to simplify a lot of the key
assumptions and take shortcuts, but they're not saying that you have to
compute everything in your mind without writing anything down. What they are
saying, however, is that you will not be able to use a calculator, so you need to
make sure that your process and your flow is at a high enough level that
you're able to demonstrate your facility your ease with math and numbers. So let
me break this down into a couple of different areas. To be excellent at math,
you will break down each math section into three different parts. The first one
is the algebra that you use. We talked in the structure section about how you
actually break down each one of the math parts, and the algebra is the structure
that you use. The assumptions are the data pieces that you use in some cases,
like market sizing cases, you will come up with the assumptions in other cases,
like standard cases, where they'll give you a chart or a graph with information
on it - the chart of the graph will serve as the data points that you'll fill in
for those assumptions that we're missing. And then finally, their calculation is
actually manipulating the numbers to come up with a new answer and come up
with an additional insight. The second thing that's important to be excellent
at math is that you can keep track of everything clearly on your paper.
This is a common issue for many of you, especially those of you that have any
history in science or the medical profession because your handwriting is
terrible, but here what they're looking for is your ability to chronicle what
you are doing in the math essentially in spreadsheet format. What that looks like
is very clearly demarcated math numbers, math calculations, and ultimate summaries
of the math. The third thing that's important is that you can confidently
double-check your numbers. So at the end of the day after you've walked through
the math very clearly - the algebra, the assumptions, and the calculations - and
you've gone through and kept track of everything by writing it down and
keeping track of it clearly on your paper, at the end you can go back and you
can say "Great, let me just double check and make sure that my numbers are
appropriate." This is going to become incredibly important when we talk about
the next part of problem-solving. Some key mistakes that we often see when
people are trying to demonstrate that they're excellent at math but not able
to do it clearly are the following. First, they don't include all the necessary data.
So for example, they may not clarify at the beginning of the math problem
what the endpoint is supposed to be. Oftentimes I give cases where the
endpoint is profit but I don't give the profit percentage - that's something that
the person, the interviewee, is going to have to ask me - so they'll come up with
this great calculation and give me all the way to revenue but that wasn't what
I was asking for. So make sure at the beginning of every math question that
you're clarifying where you're headed. And in addition, that as you're walking
through the process you're not making assumptions or giant leaps when you need
to just ask for one missing piece of data in the process. The second one is
that they don't take clear notes of their calculations. I've already talked
before about how important it is to take clear notes. If you're not able to take
clear notes when I tell you at the end that I want you to change a number,
you're not going to be able to do it. When I tell you that you made a mistake,
you're not going to be able to identify it, and you're just generally not going
to build confidence in me as your boss and manager if later when you're
actually on the job you bring me numbers, you have to be able to defend every
single one of them. And so here clear note-taking is the beginning of being
able to do that. In addition, it's really important that you do simple
calculations like division in the easy way, not the long way. If you do them in
the long way then you're making a mistake. So if you're writing out, for
example, big number multiplication or big number division and you're actually
using the dividing sign or you're using columns of multiplication, that is doing
something the long way - that's not demonstrating the kind of math that I'm
looking for. I'm looking for you to be able to take shortcuts to break down
percentages into factors of 10% to be able to identify quick ways to do
each part of your math. So again you don't have to do it without writing, but
you also can't do it the most long, arduous, and impossible way either.
So that's the beginning piece of being able to be a good problem solver - it's just
being excellent at math and clear with your notes as you're going through the process.
The next part that's really important is that you're able to quickly
realize and correct your mistakes. They happen to the best of us. Mistakes, in
fact, happened to I would imagine almost every person who goes through the MBB
process. At some point within your process, you're gonna make a small
mistake, and it is not by any means a deal breaker to make that mistake, but it
is, like I've said before in our intro video to this series, it is a deal
breaker to make the mistake and not catch it. So at the end of each part of
the process, in order to quickly realize and correct your mistakes, you're going
to be doing a few things. The first is that you'll check the answers at the end
to see if they're reasonable. If you're not sure that they're reasonable, you
need to think about a way to do that. Which brings me to the second piece - if
you're not sure whether they're reasonable, you need to triangulate your
answers. What I mean by that is think of another way that you could measure
whether or not it's reasonable. So if you come up with a number of X per household, then go
back and just try to determine is that a reasonable number, if you think about the
actual usage in the household, if you use that number in the beginning think about
another way to come at it. You're trying to come up with a second way to
corroborate your initial conclusion to make sure that you're not totally
bonkers when you're proposing it to the client. The third thing is to make sure
that if you messed up you acknowledge clearly "Oops I made a mistake. Here's
where the mistake was, let me quickly go back and fix it." If you make the mistake,
it's not an issue, but if you try to cover it up or if you acknowledge that
there was a mistake and don't show the initiative to go back and fix it, that is
a really key problem, because it's likely that
if you do that in the case interview you're gonna do that with me on the job -
which is gonna create big problems for me when I'm going to try to justify
something to a client and the numbers are wrong and then we work ourselves
into a huge nasty hole. Some key mistakes that we see in this area are the
following. First of all, crappy notes make going
back impossible. So you have to make sure you're taking clear notes in the process.
The second thing is fighting for a wrong answer. If I question your answer at the
end, you want to make sure that you also question your answer. I'm not asking for
you to defend to the death what your answer is,
I'm asking you probably to clarify why you think that answer is right. So I'm
either looking for just some additional insight, but I'm probably telling you
that you're wrong and I'm giving you the opportunity to go back and find that
error before I find it for you. The third thing that's important is making sure
that you talk through your thoughts by not talking for your thoughts so by
going silent when you're actually working through the math process, or by
just telling me the numbers but not the additional calculation steps that you're
taking behind each part. All that you're doing is giving me the opportunity to
identify errors that you're not identifying. So make sure that you're
talking through step by step the entire process so that if you make a mistake, I
see exactly where the mistake is, and I can quickly help you go back and fix it.
You also, if you get good at talking through the process, are gonna find your
mistakes more quickly. So that concludes the second part of problem solving which
is just making sure that when you do make a mistake, which often happens, just
go back and fix it, and make sure that you fix it an appropriate way. The next
thing that's critical to make sure that we understand is that you're adept at
tying data to overall conclusions. Problem solving isn't just about math, it's not
just about calculating numbers, it's also about using those numbers to tell the
client what they should do. So if the client finds that there's a growth rate
of 8% in a particular segment, what does it mean they should do? Should they focus
on that segment? If so, what kinds of resources should they think about
applying to that segment? What kind of implementation steps should they think
about using? So making sure that you're identifying how to use the data to tie
it to overall conclusions is really critical here. Let me break this out into
a couple of pieces. There are two key ways that you can tie
data to the overall solutions. The first one we call in consulting the "so-what."
Why should we care about what that amazing number is that you just
calculated? A lot of people come to the end of the process and say tada, the
number is 100 million, but they don't give me any sense of why that should
matter to the clients. Right? So the "so- what" is what the client would say right
after that. Right? A 100 million. So what? Make sure that
you are tying that to the bigger picture. The next thing that's critical in the
second part of tying it to the overall conclusion is making sure that you're
highlighting next steps. Next steps are after you've gone through the data and
identified the number. After you've identified with the "so-what" is, what this
number means to the client, then the next thing that you talk about is what the
client should do next. So those three pieces - identifying what
the data answer is, identifying what it means, and then identifying what the
client should do next is a part of every quantitative question - which is really
the key bulk of problem-solving inside cases. There are some key mistakes,
however, that you could make in these areas. So make sure that you don't fall
into one of these traps. The first one I call relief coma, it's when you finish
the math without driving to the next piece. You just get so excited that your
calculation is finished that you don't tie it to these next two pieces. Don't
fall into relief coma. Make sure that you're constantly pushing the case
forward. This relief coma is a constant symptom of people who train for just
McKinsey style cases because the interviewer is the one who generally
will ask the next question. This is one of the reasons why I really recommend
that in early on in your piece training you start out with interviewee led
training, where you're actually driving forward in the process. Because when
you're doing math you'll make sure that you tie these two pieces in. McKinsey is
still looking for these pieces - they're still looking for you to still drive the
case forward. They're just going to take the case wherever they want to go. The
next thing that's critical is that if you don't tie the "so-what" to the client's
main issue, you're really missing out on the opportunity to drive forward toward
the answer. You, at this point, could answer a math question that has no
bearing on the client's ultimate issue, and therefore you demonstrate that you
as a consultant are completely irrelevant to the clients issue.
You don't want to be irrelevant to the consultant. You want to make sure
that the answers that you're driving at are really critical to helping the
clients solve their problem. So make sure that you tie the silhouette back.
The final thing is just not including next steps. If you don't identify next steps,
you're not thinking like a consultant. Consultants make money off of next steps.
Every additional step that they take inside the scope of the case helps a
client become more satisfied, because they drive further toward implementation.
Every next step at the end of the case helps the client identify what the key
issue should be that they should focus on next, and often provides a role
opportunity for a consulting firm - which is the ultimate awesomeness because it
results in additional work for the consulting firm. So this is additionally
the third piece that you have to focus on, making sure that you're tying
everything in the problem-solving back to the original issue. The final thing
that's critical to make sure that you focus on is that you're maintaining a
focus and awareness on the hypothesis, if there is one, and also driving to the
solution. Now let me just quickly address hypothesis-driven approaches.
All consulting firms are interested in understanding what your priorities are,
where you think the key issues are. Some cases, yes or no cases - like should we
enter this market - or M&A cases, absolutely lend themselves to hypotheses.
Other cases are two parts - there's a problem identification and a solution
identification. In those cases it's a lot harder to come up with a hypothesis,
because basically there are two pieces - first what the problem is, second what
the solution is. So make sure that no matter what, whether you're using a
hypothesis or not, you do understand what the key issue is for a client. You cannot
use problem-solving effectively if you don't understand what the clients key
issues are. If you don't understand in general naturally what the client's key
issues are, make sure that you're working on articulating them in a case and that
you're prompting the partners that you're working with on case interviews
to ask you so that you make sure that you understand it. The second thing
that's critical to understand here is that every case has a core problem. So if
it doesn't have a hypothesis, make sure that you focus on the core problem, like
I was talking about before. And then the final piece of this is making sure that
you're managing the time allowance. Across the board as you're working
through the entire process of a case tying everything back to the hypothesis
means, making sure that you are on time and delivering everything
according to schedule, which in the case interview could be a very short period
of time. So just make sure that you're managing the time allowance. The key
mistake that we see in this area is when somebody is asking or answering a whole
bunch of questions but without a focus on really what the key issues are.
If you're not able to do this, then you're not demonstrating structure which we
talked about in the last video but you're also not demonstrating active
problem-solving, which is making sure that you're focused on the key problem
asking the direct questions, and only the most efficient direct questions to get
you to the answer, and then ultimately providing a recommendation for the client.
So if you tie all of these areas together you're gonna have amazing
problem-solving when you're working through the cases, you're gonna have
great notes, clear process, an amazing way to identify when you do make mistakes,
and finally the ability to tie everything back to the big picture and
drive everything back to the hypothesis. If you've got more questions about how
to solve problems inside cases, make sure that you get a copy of our
Consulting Interview Bible or work with us on a session so we can identify how you're
doing. If you've got further questions in the meantime, feel free to visit us on
the website at managementconsulted.com.