Ishikawa Fishbone Diagram: Root Cause Analysis Example

In the quest to uncover the hidden causes behind complex issues, the Ishikawa, or Fishbone Diagram, has proven to be an invaluable tool. This visual root cause analysis technique, developed by Dr. Kaoru Ishikawa, helps identify and address the underlying factors contributing to a problem. Let's delve into an Ishikawa root cause analysis example to understand its application and effectiveness.

Root Cause Analysis for Business Analysts | Venkatesh Kolluri posted on the topic | LinkedIn Root Cause Analysis, Business Analyst
Root Cause Analysis for Business Analysts | Venkatesh Kolluri posted on the topic | LinkedIn Root Cause Analysis, Business Analyst

Before we dive into the example, let's quickly recap the key steps involved in an Ishikawa root cause analysis:

Fishbone Diagram (Ishikawa Diagram) Explained | Root Cause Analysis Tool | Lean Six Sigma
Fishbone Diagram (Ishikawa Diagram) Explained | Root Cause Analysis Tool | Lean Six Sigma

Setting the Stage for Ishikawa Root Cause Analysis

Before drawing the Fishbone Diagram, it's crucial to clearly define the problem and gather a cross-functional team to ensure diverse perspectives. The team should brainstorm potential causes under several categories.

the root cause info sheet is shown
the root cause info sheet is shown

For our example, let's consider a production issue in a manufacturing company: "High defect rate in finished products". This is a well-defined problem, ready for root cause analysis.

Causes to Consider in Ishikawa Analysis

Root Cause Analysis Using Fishbone Diagram
Root Cause Analysis Using Fishbone Diagram

Ishikawa diagrams typically include categories such as 'People', 'History', 'Measures', 'Equipment', 'Methods', and 'Materials'. Let's explore these categories with our example:

  • People: Operator errors, lack of skill, high turnover rate, etc.
  • History: Changes in raw materials, past maintenance issues, etc.
  • Measures: Inadequate inspection process, flawed record-keeping, etc.
  • Equipment: Machine malfunctions, wear and tear, poor maintenance, etc.
  • Methods: Inefficient production processes, weak quality control, etc.
  • Materials: Poor quality raw materials, insufficient supplier screening, etc.

Drawing the Ishikawa Diagram

the root cause info sheet is shown in blue and white, with information about root cause
the root cause info sheet is shown in blue and white, with information about root cause

With the categories identified, the team can now draw the Fishbone Diagram with the problem at the head of the fish's head and the categories forming the spine. Brainstorm causes under each category and connect them to the spine.

Once the diagram is complete, priority scorecarding can help identify the most critical causes for deeper investigation.

Example: Application of Ishikawa Root Cause Analysis

What is Why-Why Analysis🎯 | Govind Tiwari,PhD
What is Why-Why Analysis🎯 | Govind Tiwari,PhD

Let's apply these steps to our example. The team might identify the following causes:

  • People: Lack of training (score: 8/10), High turnover rate (score: 6/10)
  • History: Change in raw material supplier (score: 7/10), Machine breakdown last month (score: 5/10)
  • Measures: Lack of inline quality checks (score: 9/10), Incomplete documentation (score: 6/10)
  • Equipment: Frequent equipment failures (score: 8/10), Inadequate maintenance (score: 7/10)
  • Methods: Inefficient production process (score: 7/10), Lack of standardization (score: 8/10)
  • Materials: Reduced material quality (score: 8/10), Insufficient supplier screening (score: 7/10)
How to apply Root Cause Analysis in mechanical engineering | Mechanical Engineering World posted on the topic | LinkedIn
How to apply Root Cause Analysis in mechanical engineering | Mechanical Engineering World posted on the topic | LinkedIn
Root Cause Analysis: Cheat Sheet for Solving(the right) Problem
Root Cause Analysis: Cheat Sheet for Solving(the right) Problem
#safetyfirst #rootcauseanalysis #ishikawadiagram #workplacesafety #cutinjuryprevention #hse #occupationalsafety #continuousimprovement #riskmanagement #safetyculture | Vivek Shahi
#safetyfirst #rootcauseanalysis #ishikawadiagram #workplacesafety #cutinjuryprevention #hse #occupationalsafety #continuousimprovement #riskmanagement #safetyculture | Vivek Shahi
a diagram that shows the steps in how to use root cause
a diagram that shows the steps in how to use root cause
SWOT Analysis: How To Use a Free Template - Shopify
SWOT Analysis: How To Use a Free Template - Shopify
Root Cause Analysis Template: Free Download + Steps [2026] • Asana
Root Cause Analysis Template: Free Download + Steps [2026] • Asana
5 Whys Excel Template /Root Cause Analysis Template | Fishbone Analysis | 5 Why Root cause Analysis/ RCA / Editable Excel file/ All in one
5 Whys Excel Template /Root Cause Analysis Template | Fishbone Analysis | 5 Why Root cause Analysis/ RCA / Editable Excel file/ All in one
the root cause analysis worksheet is shown in black and white, with an image of
the root cause analysis worksheet is shown in black and white, with an image of
the fishbone diagram is shown with different types of fish and other things in it
the fishbone diagram is shown with different types of fish and other things in it
Root Cause Analysis Template | Template Business
Root Cause Analysis Template | Template Business

With the diagram complete, the team can now focus on 'Lack of training' and 'Inadequate maintenance' as top priorities for further investigation.

Embarking on this journey of continuous improvement, it's crucial to remember that the Ishikawa root cause analysis is just a starting point. The insights gleaned should guide the implementation of corrective actions, prevention of recurrence, and ultimately, drive organizational success. So, go ahead, pick up that whiteboard marker, and let the Fishbone Diagram help you swim through complex issues with clarity and confidence.