Business Analyst Case Study Interview Template

One of the hardest things to do in the business analysis profession is find the right candidate for the right job. It is no mystery that in spite of how far we have come, no two business analysis jobs are alike. Recruiters and hiring managers seem to be able to get a sense of a business analyst’s hard skills. They can review their resume and ask direct questions regarding the knowledge and experience with techniques like use cases, user stories, context diagrams, etc. They can quiz them on the types of projects they have worked on and the different methodologies from waterfall to agile and everything in between. I know many companies that have BA candidates present requirements deliverables and have them perform some BA tasks as part of the interview process.

Even with a case study interview process, it is still difficult to get a sense of a candidate’s analytical thinking ability. Although it is difficult to determine in an interview, it is one of the skills that separate good BAs from the great BAs. I’m talking about the ones with the ability to think abstractly, then break down an abstract challenge or opportunity and turn it into a solution. In 2011, most companies can find people with the hard skills. The accepted practices used at many companies have been around long enough, so finding people with the necessary hard-skill experience is easy. What the BA does with the information elicited is the difficult part to judge. How do you know candidate one can help your team better analyze a situation than candidate two? I have the answer. You need to see how well the candidate can guess.

In a recent Time magazine article, Good Guess, Why we shouldn’t underestimate the value of estimating, the author Annie Murphy Paul made me realize I had a valid reason to make candidates take a guess during an interview. The premise of the article is that estimation is the foundation for more analytical thinking and crucial for people searching for jobs in the knowledge-based economy in which we are in.

With the ability to “just Google it,” many people, young and old, no longer take a guess or rarely estimate because many answers are at their fingertips. By not practicing with estimation, you start to lose the ability to think abstractly. In some ways, Google makes us more efficient, while in other ways it makes us lose the necessary skill to be an excellent BA.

Here is a question I ask to see how well a BA candidate can guess. How much revenue per day is made by the and Tollway Authority from cars passing through the 400 toll plaza? Depending on the answer, I can gauge an individual’s ability to think abstractly and analytically. If a candidate replies with, “Hold on, let me Google it,” I am not impressed. If they take a guess that goes something like, “There are almost 5 million people in the area and half the people are adults. Of adults that can drive, 1.5 million own cars. Of the 1.5 million, a third probably live and work in an area that would require them to go through the toll. Of that .5 million, I’ll guess half or 250,000 go through the toll each day. The toll cost per day is $1.00, so they make $250,000 per day.” The actual answer after Googling it is closer to $60,000 per day, but who cares? What you should love about that answer is the thought process.

If you want to see if your BA candidates have the ability to think critically, keep them guessing. What great questions do you ask to determine which candidate to hire? Please share with the group below in the comments.

Abstractly yours,

Kupe

Don't forget to leave your comments below.

Case study is the most important round for any analytics hiring. However, a lot of people feel nervous with the mention of undergoing a case interview. There are multiple reasons for this, but the popular ones are:

  • You need to think on your feet in a situation where there is already enough pressure
  • Limited resources available to prepare for analytical case studies. Even with the amount of content available on web, there aren’t many analytical case studies which are available freely.

From an interviewer perspective, he is judging the candidate on structured thinking, problem solving and comfort level with numbers using these case studies. This article will take you through a case study. Answer to each question takes you deeper into the same problem.

Background:

I moved to Bangalore 10 months back. Bangalore is a big city with number of roads tagged as one-way. You take a wrong turn and you are late by more than 20 minutes.  Every single day I compare the time taken on different routes and choose the best among all possible combinations. This article takes you through an interesting road puzzle which took me considerable time to crack.

Process to solve: 

I have structured this in a fashion very similar to an analytics interview. You will be provided with background at start of the interview, which will be followed by questions. After you have brainstormed / solved a question, you will be presented with additional information which will progress the case further.

If you want to undergo this case in true spirit, just ask one of your friends to take the questions and information (provided in next section) and present them to you at the right time. After all the questions, I have provided asnwers which I expect. You can compare your answers to mine.

Please note that there is no right or wrong answer in many situation and a case evolves in the way the interviewer wants. If you have a different answer / approach, please feel free to post in comments and I would love to discuss them.

Problem statement :

Background : There are two alternate roads I take to hit the main road from my home. Average speed on each of the road comes out around 30 km/hr. Let’s call the two roads as road A and road B. Total distance one needs to travel on road A and road B is 1 km and 1.3 km respectively to hit the same point on the main road . Note that, before the two roads split, I see a signal (say Z)  which is common to both the roads and hence does not come in this calculation. See figure for clarifications.

Q1 : What are the possible factors, I should consider to come up with the total time taken on each road?

Q2 : Which road should one take to reach  the main road so as to minimize the time taken? And what is the difference in total time taken by the two alternate routes?

Additional information (to be provided after question 2): Recently, one of the junction (say, X) on road A got too crowded and a traffic signal was installed on the same. The traffic signal was configured for 80 seconds red and 20 seconds green. Let’s denote the seconds of signal as R1 R2 R3 … G1 G2 G3 . Here, R1 denotes 1 sec after signal switched to red.

Q3 : Does it still makes sense to take road A, or to switch to road B provided the average speed on the road A is still the same except the halt at signal?

Additional information (to be provided after question 3):  If I reach the signal at R1, I will be in the front rows to be released once the signal turns green. Whereas, if I reach the signal at R80, I might have to wait for some time even after signal turns green because the vehicles in the front rows will block me for some seconds before I start. Let’s take some realistic guesses for the wait time after signal turns green.

R1 – R 10 : 0 sec , R11-R20 : 3 sec , R21 – R60 : 10 sec, R61 – R80 : 15 sec, G1-G15 : 5 sec, G15-G20 : 0 sec

Q4 : Does it still makes sense to take road A, or to switch to road B provided the average speed on the road A is still the same except the halt at signal?

Q5: Can you think of a reason, why road A can still be a better choice for reaching junction X in minimum time?

Additional information (to be provided after question 5): The signal Z (before the two roads split) has the exact same cycle as the signal at point X i.e. 90 sec red and 20 sec green. Average speed of any vehicle vary on road A from 25km/hr (heavy traffic) to 30km/hr (light traffic). The signal X is offset from signal Z by 25 seconds. Hence, when it turns green at Z, it is R55 at signal X.

Q6 : Does it still makes sense to take road A, or to switch to road B provided the average speed on the road A is still the same except the halt at signal?

Solution  :

Background : There are two alternate roads I take to hit the main road from my home. Average speed on each of the road comes out around 30 km/hr. Let’s call the two roads as road A and road B. Total distance one needs to travel on road A and road B is 1 km and 1.3 km respectively to hit the same point on the main road . Note that, before the two roads split, I see a signal (say Z)  which is common to both the roads and hence does not come in this calculation.

Question : Which road should one take to reach  the main road so as to minimize the time taken? And what is the difference in total time taken by the two alternate routes?

Solution : 

Background : Recently, one of the junction (say, X) on road A got too crowded and a traffic signal was installed on the same. The traffic signal was configured for 80 seconds red and 20 seconds green. Let’s denote the seconds of signal as R1 R2 R3 … G1 G2 G3 . Here, R1 denotes 1sec after signal switched to red.

Question : Does it still makes sense to take road A, or to switch to road B provided the average speed on the road A is still the same except the halt at signal?

Solution : Let’s assume I come to the signal at a random time. Hence, probability of getting to the signal at R1 R2 R3 …or G1 G2 G3 are all equal. Hence, the expected time taken at the signal is :

Background : Till this point, the solution will look good in books. Lets spice the problem up by ground realities. If I reach the signal at R1, I will be in the front rows to be released once the signal turns green. Whereas, if I reach the signal at R80, I might have to wait for some time even after signal turns green because the vehicles in the front rows will block me for some seconds before I start. Let’s take some realistic guesses for the wait time after signal turns green.

R1 – R 10 : 0 sec , R11-R20 : 3 sec , R21 – R60 : 10 sec, R61 – R80 : 15 sec, G1-G15 : 5 sec, G15-G20 : 0 sec

Question : Does it still makes sense to take road A, or to switch to road B provided the average speed on the road A is still the same except the halt at signal?

Solution :.

Background : Even after making such logical calculation, I noted that in 30 different events, I was commuting more than 25 sec faster on road A compared to road B every single time. I did not change my average velocity on either of the roads. It could have been acceptable in case I found x number of event where A wins and 30 – x where B wins. But A winning every single time was fishy. I was struggling for last 10 days to figure out a valid cause. It struck me today and following is what I figured out:

The signal Z ( before the two roads split), which I initially though had nothing to do with the calculation was actually the game changer. Here is how it played a role.  This signal had the exact same cycle as the signal at point X i.e. 90 sec red and 20 sec green. Whenever, the two lights have the same cycle, the incidence on signal X is no longer random.

Question : Does it still makes sense to take road A, or to switch to road B provided the average speed on the road A is still the same except the halt at signal?

Solution : 

End Notes

Did you find the article useful? Share with us any other problem statements you can think of. Do let us know your thoughts about this article in the box below.

In one of the upcoming articles, we will share how an interviewer judges an analyst during a case study.

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