Root Cause Analysis (RCA) cases are probably the most common cases asked in product interviews and for a good reason too.
RCA cases let the interviewer assess your product sense and judge how well you can examine the product from different perspectives.
Furthermore, these cases allow the interviewer to test whether your thinking is structured.
Let us see how one can approach an RCA case by taking an example.
Consider the Following Case
Problem
The number of cart additions on Flipkart has been reduced by 10% in the past three days.
Root Cause Analysis
Step 0: Understand the problem thoroughly.
Feel free to ask questions to get a clear picture of the problem. Concerning our case, the following questions might be of help
- Is it a gradual decrease or a sudden fall?
- Has it been observed all over the country or only in specific regions?
- Is it specific to any category of items or is it spread across all categories?
- Has it been observed across all platforms, specifically on the web or mobile?
Remember that when the case is posed, even the interviewer might not have a specific root cause in mind. Instead, they keep the case going until they are satisfied with the approach you are taking to solve the said case.
Let’s say, based on the above questions you gathered that the decrease is sudden, the issue has been observed all over the country across all categories, and only on the web application.
Step 1: Review.
Before estimating the possible reasons for the issue, a good product manager always crosschecks the credibility of the analytic tools used to pinpoint the problem. So, it is always a good idea to ask the interviewer whether you can assume that all the analytic tools used are credible.
Step 2: Look for the impact of external factors.
If you have some experience in the engineering team, your first instinct might be to enquire if there is something wrong with the application. So naturally you would want to get the application tested thoroughly concerning the affected functionalities.
But before you spend resources on testing the application, it is wise to look into external factors. For our case, the following questions help us understand if the problem is due to any external factors.
- Did the competitors release any lucrative offers in the past few days that took away the customers?
- Were there any socio-political or economic developments in recent times that affected the buying decisions of the user?
- Was there any bad PR about Flipkart in the media in recent times?
Let us assume none of these happened in recent times ruling out the possibility of external factors being the root cause of the problem.
Step 3: Investigate for inconsistencies in the application.
The natural next step would be to investigate for any inconsistencies in the application that potentially might be blocking the user from adding products to the cart.
This will be taken up by the Quality Analysis team to perform regression testing on the application specifically targeting the affected functionality.
In most, if not all, this is the last step in the root cause analysis and problems would’ve been identified at one or even multiple steps of the process.
