fishbone diagram steps

Fishbone diagrams are powerful visual tools often used to identify the root causes of problems or issues. Also known as cause-and-effect diagrams, they help organize complex information and thoughts. Here, we'll guide you through the steps of creating a fishbone diagram, ensuring you understand how to make the most of this problem-solving technique.

Fishbone diagrams are particularly useful in Six Sigma and Lean management but can be applied in any setting where you need to systematically analyze a problem. They're called 'fishbone' because, when completed, the diagram resembles the skeleton of a fish, with a horizontal line representing the problem or effect and the 'bones' or lines branching out to represent the causes.

Drawing the Basic Structure

The first step in creating a fishbone diagram is to establish the basic structure. This foundation will help you organize and categorize the causes of the problem.

Start by drawing a horizontal line to represent the problem or effect you're analysis. At one end, write the problem in a box. Then, add a 'fish head' (a vertical arrow) to the other end of the line to symbolize the start of the causes.

Identifying Major Cause Categories

Next, identify the major categories of causes that could contribute to the problem. These are typically the same across manufacturing, service, business, or any other industry. The most common categories are:

• Methods
• People
• Machines
• Materials
• Measurement
• Environment
• Management

These categories serve as 'branches' of your fishbone diagram. Draw these from the 'head' of your fishbone and label them accordingly.

Branching Out Causes

After identifying the major categories, it's time to dive into the details. For each category, brainstorm and list all possible causes of the problem. Be thorough and consider all aspects of each category to ensure you've captured all potential causes.

Write each cause along another line branching out from the category line. This creates the 'bones' of your fish. You can continue to 'branch out' as much as you need for each category, diving into more and more specific causes.

Refining the Diagram

With a complete draft of your diagram, it's time to refine and ensure it accurately represents the cause-and-effect relationships. Check that each cause is a true root cause, meaning it's a cause you can control and it directly affects the problem. Also, ensure each cause is single and clear, not a combination of causes.

Verifying Root Causes

Thoroughly verify that each cause is indeed a root cause. Sometimes, what seems like a cause might actually be an effect of another cause. Use the '5 Whys' technique to ensure you've got the true root causes on your diagram:

1. Ask why the problem occurs.
2. For each answer, ask why again until you can't ask why anymore.
3. Each 'why' should bring you closer to the root cause.

Be prepared to modify your diagram based on what you learn during this verification phase.

Final Review and Sharing

After ensuring your fishbone diagram accurately represents the cause-and-effect relationships, review the diagram with your team or stakeholders. This can help you identify any oversights or gather different perspectives on the causes. Afterward, prepare the diagram for presentation, ensuring it's clear, easily understandable, and presents the key takeaways.

Fishbone diagrams are an invaluable tool in problem-solving, helping visualize complex issues and guiding you towards effective solutions. With a well-constructed fishbone diagram, you'll be well on your way to addressing and eliminating the root causes of your problems.