What's the root cause?

Meaning

What is the fundamental reason for the problem?

Examples

• John: The project is behind schedule.
• Alice: Why is that? <b>What's the root cause</b>?
• John: We underestimated the complexity of the task. Therefore, <b>what's the root cause</b>? We need to have more realistic estimates.
• Alice: Agreed. Let's implement a better planning process.