Root cause analysis is a process used to identify the underlying reason(s) for an issue or problem. It involves investigating the symptoms of a problem and uncovering the underlying causes to find an effective solution. An Ishikawa diagram, also known as a fishbone diagram or cause-and-effect diagram, is a tool that helps to identify the potential causes of a problem.

The iceberg model, on the other hand, is a model used to visualize the different layers of a problem. The model suggests that there are visible symptoms of a problem on the surface, but the root causes of the problem are often hidden beneath the surface, much like an iceberg.

Understanding Root Cause Analysis and Why it’s Important

Root cause analysis is important because it helps to identify the underlying reasons for a problem, rather than just addressing the symptoms. By addressing the root cause, it is possible to find an effective solution that will prevent the problem from happening again.

How to Create an Ishikawa Diagram for Root Cause Analysis

To create an Ishikawa diagram, you start with the problem or issue at the center of the diagram. Then, you identify the major categories of potential causes that may contribute to the problem. 

These categories are typically labeled as the “6Ms”: Manpower, Method, Material, Machine, Measurement, and Mother Nature. From there, you can brainstorm potential causes within each category and create a cause-and-effect diagram to help visualize the relationships between the different causes.

Using the Iceberg Model to Uncover Hidden Causes

The iceberg model can be used to identify the hidden causes of a problem. The visible symptoms of the problem are listed above the waterline, while the root causes are listed below the waterline. By examining the different layers of the problem, it is possible to uncover the underlying causes that may not be immediately apparent.

Tips for Brainstorming and Identifying Potential Causes

When brainstorming potential causes, it is important to encourage open and honest communication. All team members should feel comfortable sharing their ideas and perspectives. It can also be helpful to use tools such as the 5 Whys or the Pareto chart to help identify the most likely causes.

Analyzing and Prioritizing Causes for Effective Solutions

Once potential causes have been identified, it is important to analyze and prioritize them to find the most effective solution. The causes can be evaluated based on their impact, likelihood, and cost. From there, solutions can be developed that target the root cause of the problem.

Implementing Solutions and Monitoring Results

After a solution has been identified, it is important to implement it and monitor the results. This will help to ensure that the solution is effective and that the problem does not recur.

Case Studies and Examples of Successful Root Cause Analysis with Ishikawa Diagrams and the Iceberg Model

There are many examples of successful root cause analysis using Ishikawa diagrams and the iceberg model. For example, a manufacturing company used an Ishikawa diagram to identify the root cause of a high rate of defective products. By identifying the root cause and implementing a solution, the company was able to reduce its defect rate significantly.


Root cause analysis is an important process for identifying the underlying causes of a problem and finding an effective solution. The Ishikawa diagram and the iceberg model are two tools that can be used to make the process more effective. By using these tools and following the tips outlined in this article, you can improve your ability to identify and solve problems in a smart way.


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