Fishbone (Ishikawa) Diagram Template For Root Cause Analysis

For quality managers and operations leaders, Root Cause Analysis (RCA) is a common systematic process used to identify the underlying causes of issues on the shop floor.

By focusing on resolving the primary causes of challenges, rather than merely addressing the symptoms, organizations can implement more effective and permanent solutions. This approach not only helps in problem resolution, but also plays a vital role in preventing future occurrences.

Among the various RCA methodologies that have been developed over the years, the fishbone diagram offers a distinctive approach to uncovering the underlying causes of specific problems. Its strategic application can lead to more insightful solutions and sustainable improvements across a manufacturers’ operations.

In this post, we’ll explore the value of a fishbone diagram as a tool to guide root cause analysis, the benefits of this methodology, and how you can leverage it to drive continuous improvement across your operations.

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The Fishbone Diagram, also known as the Ishikawa Diagram, is a visual technique for problem-solving invented by Kaoru Ishikawa, a Japanese quality control expert. In manufacturing, the Fishbone Diagram is an effective technique for causal analysis. It aids people in identifying potential causes of a problem and is an especially helpful brainstorming tool when problem-solving is blocked and little quantitative data is available.

The benefits of a Fishbone Diagram analysis

A Fishbone analysis allows businesses to carry out a systematic breakdown of any problem. Its main advantages include the following:

Targeted Visualization

A Fishbone Diagram offers visual clarity. It maps the various causes of an issue and makes links between them that you might otherwise overlook. As a business, you can eliminate false positives and focus on critical areas that need attention.

Determines Bottlenecks and Solutions Efficiently

Visualizing cause-and-effect relationships can help you identify bottlenecks more effectively. This results in speedier solutions.

Improvement-Oriented Approach

A fishbone root cause analysis identifies gaps and areas for improvement in your systems and processes. Dissecting each probable cause repeatedly can drive adjustments and help shape processes more effectively.

Enhances Team Understanding

A visual mind map of the potential causes of a problem can help employees better understand their roles in the process. A key step in fishbone analysis is brainstorming. It helps employees think outside the box and break rigid thought patterns.

The Fishbone Diagram is usually read from left to right and consists of bones, indicating possible causes of a problem, connected to a spine leading into the fish’s head, which symbolizes the defect or problem.

For example, in the diagram below, the shape of a fish’s skeleton is formed by possible causes, grouped by category, for a failed inspection.

Here, the causes are categorized by the “5 M’s” in manufacturing:

• Machine: Any equipment and machinery used in production or service

• Method: The standardized steps, instructions, or processes a business outlines for delivering a product or service.

• Material: Any tangible or intangible component used in production or service. For example, ingredients, consumables, tools, or raw materials.

• Manpower: The staff or team members involved in the production process. Potential causes related to “manpower” could include loss in employee morale or a lack of skills or competencies.

• Measurement: The metrics used to track and measure processes. For example, KPIs, data, output, or delivery time.

Practical example

Using the 5 M’s as prompts to generate hypotheses for the root cause of a problem, you write the potential causes under each of these on the “ribs” of the fish. In the image below, for example, the problem is that 12% of the product fails inspection, and one of the potential causes of this related to the materials is that screws were worn.

By visually sorting possible defect causes, identifying cause and effect relationships, and determining which causes are having the greatest impact on the problem, the Fishbone Diagram enables people to address the problem rather than its symptoms.

The following steps will help you get started using a Fishbone Diagram for root cause analysis on your shop floor:

Identify a Problem Statement: This is the “effect,” aka the main problem, represented by the fish head. A problem statement needs a clear and precise definition. Consider using criteria like SMART (specific, measurable, achievable, relevant, and time-bound) to define a problem concisely.

Brainstorm the Main Causes and Categorize Them: Gather people from diverse teams to help identify the "Why" behind each cause. This includes referring to the 5Ms and categorizing each possible cause using these components.

Delving Deep Into Specific Causes: After outlining the probable causes, it’s critical to identify the underlying cause. This means asking questions like “Why did this happen?” You can include these as sub-causes beneath each branch.

Analyzing and Prioritizing Root Causes: After mapping down all causes, the next step is to analyze each one. During analysis, each cause is typically prioritized based on its contribution to the problem.

The Fishbone Diagram isn’t a new concept, but remains an effective too for problem-solving in modern-day businesses. By enabling a structured breakdown and visual mapping of causes, it empowers teams to identify and address underlying problems effectively.

Tulip complements this RCA methodology by providing manufacturers with real-time data, making it easier to spot patterns and anomalies across production processes. This capability supports quality managers in making informed decisions quickly, ensuring that corrective actions are timely and effective.

By leveraging Tulip alongside the fishbone diagram, organizations can not only solve existing problems more efficiently but also build a proactive culture of quality and continuous improvement, aligning daily operations with strategic objectives for long-term success.

If you’re interested in learning how Tulip can be used to improve your quality management processes, reach out to a member of our team today!