Fishbone Diagram

Fishbone Diagram – A Guide to Problem Solving

Overview

A fishbone diagram, also known as an Ishikawa diagram or a cause-and-effect diagram, is a problem-solving tool used to identify the root causes of a problem.

It is an effective way to visualise the different factors that contribute to a problem and helps to identify the most likely causes of the problem.

Many well-known global brands have used this strategy to solve complex problems.

For example:

• Toyota used a fishbone diagram to identify the root cause of defects in their manufacturing process. They found that poor quality control was the root cause of the defects and were able to implement changes to improve the quality control process.
• McDonald’s used a fishbone diagram to identify the root cause of long wait times in their drive-thru. They found that a lack of staff and inefficient processes were the root cause and were able to implement changes to improve the drive-thru experience for their customers.

Using a fishbone diagram can help businesses to solve problems more efficiently and effectively, leading to improved productivity, customer satisfaction, and profitability.

How to

Here are the steps to create a fishbone diagram:

1. Identify the problem that needs to be solved.
2. Write the problem statement on the right-hand side of the diagram.
3. Draw a horizontal line to represent the spine of the fish.
4. Identify the major categories of factors that could contribute to the problem. These are typically represented as “bones” on the fish. Examples of categories include people, processes, equipment, and environment.
5. Draw diagonal lines from the spine to each of the “bones”.
6. Identify the specific factors that contribute to the problem within each category and write them on the diagonal lines.
7. Identify the root causes of the problem by looking for common themes or factors that appear in multiple categories.
8. Develop solutions to address the root causes of the problem.

Best practices

• Involve a cross-functional team in the problem-solving process to ensure all perspectives are considered.
• Focus on the problem, not the symptoms.
• Use data to support the identification of root causes.
• Be open to multiple perspectives and ideas.
• Test and validate solutions before implementing them.
• Continuously monitor and evaluate the effectiveness of the solution.

Examples

Here are two potential examples of how small businesses could use a fishbone diagram:

1. A restaurant is experiencing a decline in customer satisfaction ratings. They use a fishbone diagram to identify the root causes of the problem and find that the quality of the food, the service provided by staff, and the cleanliness of the restaurant are the main factors contributing to the decline. They implement changes to address these factors, such as improving the training of staff and increasing the frequency of cleaning, and see an improvement in customer satisfaction ratings.
2. A manufacturing company is experiencing a high rate of defects in their products. They use a fishbone diagram to identify the root causes of the problem and find that the quality of the raw materials, the manufacturing process, and the equipment used are the main factors contributing to the defects. They implement changes to address these factors, such as sourcing higher quality raw materials and implementing a more rigorous quality control process, and see a reduction in the rate of defects.