The 5 Why’s method is a deductive root-cause analysis technique.
The technique consists of asking “why” at least five times while reaching the root cause of a problem to solve. Indeed, from experience, stopping at two or three degrees of “why” does not necessarily lead to the actual root cause of a problem. To solve problems effectively, you must identify the root causes and ensure your solutions directly address them.
Therefore, here are key points to consider while using the 5 Why’s technique:
- Be grounded in reality: at each level of “why,” go and see facts to verify that it is a “real” cause.
- Trace back the chain of causality in the opposite direction to verify that the cause identified at level N-1 directly and indisputably generates the cause at level N.
- You might need more or fewer levels for the “whys,” depending on the cases.
We want to go deeper enough to uncover the fundamental reason for the problem, enabling effective and sustainable solutions.
Identifying root causes is not exclusively a matter of mental reasoning. It needs to come from reality. Thus, each root cause hypothesis requires a confirmation method. The latter is a fact observation where operations are happening or even local experimentation to confirm the root causes hypothesis.
Identifying root causes is crucial while conducting a problem-solving approach (for example, a PDCA).
Example
A large e-commerce company notices a significant drop in website traffic and sales. The simple cause appears to be slow page load times. However, upon thorough investigation, the root cause is outdated data architecture. This root cause led to multiple contributing issues:
- Inefficient database queries
- Overloaded servers during peak times
- Difficulty in implementing new features
- Inconsistent user experience across devices
The company can solve these multiple issues by addressing the root cause (redesigning the data architecture) rather than just optimizing the existing system. This approach improves the current performance and enables better scalability and feature implementation for future growth.
This example demonstrates how a fundamental architectural issue in IT and digital systems can be the root cause of various performance and user experience problems. Addressing this root cause provides a more comprehensive and long-lasting solution than treating each symptom individually.