How to Approach the Case Study Question in an MBA Interview

The case study question in an MBA interview will require you to solve a real-time problem; here is an example, "The government is planning a new parking facility for the New Delhi International Airport. What should be the capacity for this parking structure?" The purpose of such questions is to judge the candidate's aptitude for solving complex business problems. While case study questions are common in management job interviews, especially in consulting profiles, they are not typically asked in pre-MBA interviews; however, they are occasionally bought up in the MBA interviews for schools where consulting is a prominent post-MBA option. For instance, ISB's MBA interviews often include case study questions. In a sense, you can consider the case study question a prelude to your MBA job interview. Before reading further, you might want to try to solve the previously mentioned question yourself.

Broad Tips

We will begin our examination of the MBA interview case study questions with a few broad tips that will form the basis of your approach. First of all, begin by seeking time from the interviewer; you will need it to formulate your answer. Once you have time to work, break the problem down into as many dimensions as possible. While working on the problem, make sure to always carefully consider the situation described in the question and only assume sensible numbers. One very important tip to bear in mind, while working on the MBA case study question, is to lay emphasis on your process. The interviewer's goal in asking this question is not to see how accurate an answer you can deliver; it is to test your aptitude /approach for solving complex business problems.

Example

To illustrate this approach, we will now solve the problem mentioned at the beginning of this article, "The government is planning a new parking facility for the New Delhi International Airport. What should be the capacity for this parking structure?" Remember, the two fundamental steps to solving a case study question are breaking down the problem to cover as many dimensions as possible, and assuming reasonable numbers; we will now demonstrate how to conduct both these steps, effectively.

Break the Problem

The very first thing to do, when breaking down the problem, is to identify exactly what has been asked; in this case, the required capacity of the parking structure. Next, you must identify all of the variables that must be taken into account; remember, there is no one correct way to tackle this stage of the case study question, but you must think deeply to make sure that you take into consideration the variables whose importance is not immediately apparent.

For this question, the variables that we will be considering are as follows:

-The number of gates at the airport
-The number of flights per hour per gate
-The average operational hours per gate
-The average number of passengers per flight
-Incoming passengers
-Passengers traveling in groups
-Percentage of travelers using the parking
-Airport employees
-Average parking time
-Peak load capacity
-The margin for capacity expansion.

Assume Reasonable Numbers

Now that we have broken the question into more than ten constituent parts, we will take a look at how to fill in numerical values for each that fall within an acceptable and logical range. We suggest that, before reading further, you take a moment to try and fill in the values yourself, to understand how reasonable your assumptions currently are.

The number of gates - Considering the large population of Delhi, the airport must have a large number of gates. 100-200 gates would be an unreasonably high estimate, but 50 seems reasonable.

Flights per hour per gate - Let us assume that a plane leaves from each gate at 45-minute intervals and take this variable to be one per hour, for the sake of simplicity. An estimate of four or five flights per hour would not be reasonable.

Average operational hours per gate - Naturally, the gates will not be in operation 24 hours a day, a reasonable estimate here would be 18 hours, per day.

The average number of passengers per flight - Th number of passengers on any given flight can vary between 100 and 400; however, as not every flight will be filled to capacity, the average should be on the lower side. Let us take it to be 200.

Incoming passengers: Logically speaking, the number of incoming passengers should be quite close to the number of outgoing passengers. In order to determine the number of outgoing passengers, we need to multiply our previously ascertained variables; this comes out to approximately 200, 000, after rounding up. So, the total number of passengers passing through the airport on an average day is 400, 000.

Passengers traveling in groups: Since a decent percentage of passengers will be coming to the airport together, let us assume 40%, the total number of vehicles that the parking must be built to accommodate will be lower. However, we cannot simply subtract 40% of 400,000 from the total number of passengers, as even passengers traveling in groups will contribute to the total number of vehicles. It would be prudent to assume that passengers traveling in groups will reduce the number of vehicles by 20%. Thus, our new base number of passengers is 320, 000.

Percentage of travelers/co-visitors using the parking- One very important logical point to take into account here is that not every passenger will require parking; in fact, a large number of passengers will probably take a cab or public transportation, as airport parking tends to be expensive. In all likelihood, even assuming that 20% of the passengers will use the airport parking is unreasonable; a more fitting estimate would be 15%. With this estimation, we can conclude that the total number of cars that will be housed in the parking facility, each day, is around 48, 000.

Airport employees - 2000 is a reasonable number of employees for us to assume that the airport employs; however, in all likelihood, most of them will not use the airport parking. Keeping this in mind, let us round up our previous estimate to approximately 50, 000 cars housed in the parking facility, per day.

Average parking time - The amount of time that each car will be parked will vary greatly; some will only be parked for a few minutes, while others may remain in the structure for several days. Keeping these factors in mind, we can reasonably assume that the average parking time is one hour. Half an hour would also be a reasonable assumption but any lower than that would not. Taking this one-hour estimate, we can conclude that the number of vehicles in the parking facility at any given time would be 50, 000 divided by 24, approximately 2, 000.

However, 2,000 is only the average number of cars; we need to also consider peak load capacity. There will be times when the number of cars in the facility is far lower than 2, 000, but there will also be times when it will be far higher, and the facility must be constructed as per the peak capacity requirements. Let us assume that the peak capacity requirement is 100% more than the average requirement; thus, the peak load capacity is 4,000 cars.

Finally, we must also account for the margin for capacity expansion. This margin should not be assumed to be very high; 20% is a reasonable estimate. Therefore, our final answer is 4,800; the parking facility should have the capacity to house 4, 800 cars at any given point in time. If you happen to disagree with this number, that is fine. The purpose of this exercise was very much to explain the approach for tackling the MBA interview case study question.

For a more complete understanding of MBA interview preparation, please read the other articles prepared by Experts' Global.