How to Use a Fishbone Diagram for Root Cause Analysis

Ima F.
Sep 4, 2024

Getting to the root cause of an issue is the key to preventing it from recurring.

That’s where root cause analysis comes in—by digging deeper to uncover the underlying causes of an issue, organisations can implement more effective and permanent solutions that last, rather than just treating the symptoms.

One of the most effective tools for this is the fishbone diagram, a powerful visual tool used to dissect complex problems and systematically uncover the root causes.

In this article, we’ll explore how to use this diagram effectively to streamline your problem-solving process and achieve more sustainable results.

What is a Fishbone Diagram?

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

The diagram gets its name from its fish-like shape, where the “head” represents the problem or effect, and the “bones” branching off represent different categories of potential causes.

Originally developed by Japanese quality control expert Dr. Kaoru Ishikawa in the 1960s to support quality management processes, Ishikawa diagrams have become a staple in root cause analysis across various industries. This diagram-based technique is particularly effective at breaking down complex problems into manageable parts, allowing teams to explore and understand all possible contributing factors.

Rather than being static, it evolves with new information, making it a dynamic problem-solving tool. Teams often develop fishbone diagrams collectively, incorporating insights from various members to ensure a comprehensive analysis.

Collaborating in this way fosters a unified understanding of the issue, which ultimately leads to more effective solutions and helps prevent the problem from recurring in the future.

Key Elements of a Fishbone Diagram

Fishbone diagrams are structured to resemble a fish skeleton, with several key elements that work together to identify and analyse the root causes of a problem.

Fishbone diagram example

The Head (Problem Statement)

The “head” of the fishbone diagram represents the problem or effect that you are trying to solve. It is placed at the far right of the diagram and serves as the focal point for the analysis.

A clear and concise problem statement is crucial because it guides the entire process, ensuring that the analysis remains focused on the specific issue at hand.

Main Bones (Major Categories)

The “bones” branching off from the spine of the fish represent major categories of potential causes. These categories represent major causes or factors that contribute to the problem.

The categories are typically broad and can vary depending on the industry or type of problem being analysed. Common categories include:

  • People: Issues related to human factors, such as lack of training, communication breakdowns, or human error.

  • Methods: Problems arising from processes or procedures, such as inefficient workflows or unclear guidelines.

  • Machines: Equipment or technology-related causes, like machine malfunctions or outdated software.

  • Materials: Issues with the materials used, such as low-quality inputs or supply chain disruptions.

  • Measurements: Errors in data collection, measurement inaccuracies, or misinterpretation of data.

  • Environment: External factors like workplace conditions, regulatory changes, or environmental impacts.

Sub-Bones (Potential Causes)

Each major category branches into sub-bones, which represent specific potential causes within that category. These sub-bones further break down the problem, helping to drill down into the root causes.

For example, under the “Machines” category, sub-bones might include “lack of maintenance,” “software bugs,” or “operator error.”

The Spine (Central Line)

The spine of the diagram is the central line that connects the head to the major categories. It serves as the backbone of the diagram, linking the problem statement to the various causes being explored.

The spine keeps the analysis organised and visually connects all the elements of the diagram.

Steps to Create a Fishbone Diagram

Let’s walk through the steps to create a fishbone diagram for root cause analysis:

1. Define the problem statement

The first step in creating a fishbone diagram is to clearly define the problem statement. This is the “head” of the fish, and it should be a concise description of the issue you’re trying to solve.

The problem statement should be specific, detailing how and when the issue occurs for better clarity. For example, instead of stating “Production delays,” a more precise statement would be “Production delays in the assembly line during peak hours.”

The problem statement should be specific enough to guide the analysis but broad enough to encompass all potential causes.

Take time to ensure that everyone involved has a shared understanding of the problem, as this will keep the analysis focused and effective. Once defined, place the problem statement at the head of the fishbone diagram to serve as the focal point for the subsequent steps.

2. Identify major categories

After defining the problem statement, identify major categories that could be contributing to the problem.

These categories, acting as the main bones extending from the fish’s spine, represent major factors contributing to the problem.

For different industries, the categories can vary depending on context. In manufacturing, you might include machines and materials, while in healthcare, categories like processes and environment might be more relevant.

The goal is to group potential causes into broad areas that will help organise your analysis. Once you’ve determined the relevant categories, label each bone with one of these categories, setting the stage for a deeper exploration of potential causes in the next steps.

3. Brainstorm potential causes

With your major categories in place, the next step is to brainstorm specific potential causes that fall under each category. Think of these as the “sub-bones” that branch off from the main bones of the fishbone diagram.

Gather input from those with relevant knowledge or experience and consider all factors that potentially contribute to the problem, no matter how minor they may seem. The goal is to generate a comprehensive list of potential causes for each category.

As you identify these causes, add them to the diagram, connecting them to the appropriate category bone. This process will help you visualise the full range of factors contributing to the problem, setting the stage for a thorough root cause analysis.

4. Analyse and identify root causes

Now your fishbone diagram is fully populated, it’s time to analyse the information and identify the root causes of the problem.

Start by examining each branch of the diagram, looking for patterns or recurring themes across different categories that might indicate a deeper issue.

The “5 Whys” technique can be useful here. This involves repeatedly asking “why?” to uncover deeper layers of the problem down to the root cause.

Through this analysis, you should be able to pinpoint the most significant factors that, if addressed, will likely resolve the problem. This deeper analysis ensures that the solutions developed are effective and long-lasting.

5. Prioritise and address root causes

After identifying the root causes, the final step is to prioritise and address them.

Not all root causes will have the same impact on the problem, so it’s important to evaluate which ones have the most significant impact and are the most critical to resolve.

Start by ranking the root causes based on factors such as their severity, the ease or difficulty of addressing them, and the potential impact of their resolution.

Once prioritised, develop a corrective action plan, tackling the most significant root causes first. This plan should include specific steps, responsible individuals or teams, and a timeline for implementation. It’s also essential to consider any resources or support needed to address these causes effectively.

As you begin to implement your solutions, monitor the progress and effectiveness of the actions taken. Based on feedback and results, adjust your approach as necessary to ensure that the root causes are thoroughly resolved.

By prioritising and systematically addressing the root causes, you effectively solve the current problem and reduce the likelihood of it recurring. This approach leads to more sustainable improvements in your processes and operations.

Benefits of Fishbone Diagrams

Using a fishbone diagram offers several key benefits that enhance problem-solving and drive continuous improvement:

  • Targeted Visualisation: The fishbone diagram visually maps out potential causes and their connections, making it easier to identify overlooked links and understand the relationship between the problem and its causes.

  • Improvement-Oriented Approach: By systematically analysing each potential cause, the diagram helps identify gaps and areas for improvement, driving continuous process enhancement.

  • Enhanced Decision-Making: With a clear layout of all potential causes, the diagram aids in identifying root causes and prioritising the most critical issues, leading to more strategic and well-informed decisions.

  • Encourages Collaborative Problem-Solving: Involving diverse perspectives, the fishbone diagram fosters collaboration and innovation, ensuring a comprehensive analysis of the problem from all angles.

  • Prevents Recurring Issues: By focusing on root causes rather than symptoms, the diagram helps prevent problems from recurring, leading to long-term improvements.

Summary

Tackling the root causes of problems is essential for any organisation that wants to implement lasting solutions rather than just patching over the symptoms.

The fishbone diagram is an invaluable tool in this process, offering a clear and structured way to dissect complex issues and drill down to the root causes.

Beyond its practical use, the fishbone diagram also fosters a culture of collaboration and continuous improvement, helping teams see connections they might have missed and prioritise the most impactful solutions.

Vatix’s incident reporting software complements this root cause analysis method by providing valuable data and insights, allowing teams to identify trends, track recurring issues, and make more informed decisions. This data-driven approach helps teams prioritise root causes more effectively, address problems before they escalate, and create more targeted, long-lasting solutions.

To discover how Vatix can help streamline your root cause analysis processes and enhance operational efficiency in your organisation, talk to our sales team here.

Latest posts

View all posts

Understanding the Worker Protection Act: A Guide for Employers

What is the Worker Protection Act? The Worker Protection Act 2023 (sometimes referred to as the Worker Protection Bill) is a significant update to the existing Equality Act 2010, designed to strengthen protections for employees and create safer, more inclusive workplaces. This new legislation introduces a positive legal duty for employers, requiring them to take…
Read post

Implementing the Golden Thread: Best Practices for Construction Companies

What Is the Golden Thread? In the construction industry, ensuring the safety of buildings and their occupants is paramount. Much like Mandatory Occurence Reporting, the concept of the golden thread has emerged as a vital framework for achieving this goal. But what is the golden thread, and why is it so important? Simply put, the…
Read post

How to Navigate Ofsted Supported Accommodation Inspections

What is Supported Accommodation? Supported accommodation (sometimes referred to as Ofsted semi independent living) is a type of living arrangement specifically designed for care leavers and looked-after children aged 16 and 17 who have been placed by the local authority. As these young people prepare to transition into adulthood, supported accommodation provides them with a…
Read post

Elevate Safety & Operations with Vatix

Join 500+ forward-thinking leaders enhancing safety and operations
Contact Us