Define the problem more clearly:

The first step is to validate the problem and understand its specifics. We need to verify whether this drop in completion rate happened suddenly or has been gradual over time. I would also want to know whether this drop is isolated to Chennai or if there are similar patterns across other cities.

Segment the data:

Next, we would need to segment the data. This could include looking at different courses, age groups, genders, or job levels. Are there specific segments that are experiencing a larger decrease? Segmentation will help us narrow down the problem and could provide clues as to what might be causing it.

Identify internal factors:

Look at any changes in the course structure, platform, or any related internal events that happened around the time the drop started. This could include changes in course content, instructor, or platform UX/UI, or technical issues like increased app crashes or slow video streaming. I would also check with the customer service team to see if there has been a rise in specific complaints from Chennai.

Identify external factors:

This could include events like a major competitor launching a similar course, changes in industry demand for certain certifications, or even local events like prolonged internet shutdowns or natural disasters.

Analyse other related metrics:

See if there has been a change in other metrics like new user signups, course drop-outs midway, user engagement, user feedback scores, etc. This could give us more insight into where in the user journey we are facing issues.

Develop hypothesis and experiment:

Based on the data and insights gathered, develop a hypothesis about why the completion rate is decreasing. For example, if the drop is most significant among working professionals, one hypothesis could be that the course workload is too high for people working full time. Once a hypothesis is formed, we can then devise tests to confirm it, like surveys or A/B tests.

Develop a mitigation plan:

Once the root cause is identified, a detailed action plan needs to be put in place to address the issue. This could involve improving course content, changing course structure, improving platform stability, or running promotional campaigns.

In summary, an 18% decrease in the certification completion rate is significant and requires immediate attention. A structured problem-solving approach will help identify the root cause and formulate the appropriate solution to address the issue.