Ishikawa Fishbone Diagram: Problem-Solving Made Easy

When it comes to problem-solving for factories, few are as versatile as the Ishikawa Fishbone Diagram.

It’s easy to implement, highly effective and, if done correctly, will not only solve the problem but prevent it from happening again.

Let’s take a look.

What is Ishikawa Fishbone Diagram?

The Fishbone Diagram gets its name from its resemblance to a fish skeleton. It has many names too, so you might know this method as Ishikawa Diagram or Cause-and-Effect Diagram.

Ishikawa Fishbone Diagram is a visual tool that helps you identify the potential causes of a specific problem by categorising potential causes into different branches.

This is a very structured approach to problem-solving analysis, which makes it easier to follow as the steps are always the same.

How does Ishikawa Fishbone Diagram work?

First of all, and key to any problem-solving process is identifying the problem you’re dealing with.

Once you do this, you write it in your diagram. This will become the head of your fish.

Once done, draw a horizontal line across the page, and the rest of the fish bones —or branches— extending from it.

Each bone represents a different category of potential causes related to the problem you’re addressing.

Some of the most common categories include:

  • People
  • Processes
  • Equipment
  • Materials
  • Environment

Once you have your fishbone diagram set up, lead a brainstorming session with your team to identify the causes for each category. For instance, under processes, you might identify sub-categories like lack of standardisation or inefficient workflow.

How to do an Ishikawa Fishbone Diagram step-by-step

The Fishbone Diagram is a structured approach to identifying potential causes of a problem. It follows a systematic approach to problem analysis, and it consists of 9 easy steps:

Ishikawa Fishbone Diagram step by step

mlean® Fishbone Diagram


Step 1 —Define the problem

Be as specific as possible during this step. Define the problem as clearly and factually as you can.

Step 2 —Draw the spine

Draw a horizontal line across your page originating from the problem statement. This line represents the spine of the fish.

Step 3 —Identify the main factors

Identify the main factors that could contribute to the problem. Common categories include people, processes, equipment, materials, and environment. This will serve as the bones of the fish.

Step 4 —Add sub-branches

Draw diagonal lines from each category bone to create sub-branches. These sub-branches represent potential causes within each category. For example, under the processes category, you might identify sub-branches like lack of standardisation or inefficient workflow.

Step 5 —Explore causes

Continue adding sub-branches until you’ve explored all possibilities. Encourage your team to contribute their insights and ideas.

Step 6 —Analyse relationships

Examine the relationships between the causes identified in the sub-branches. Look for connections and patterns. This step helps you understand the interactions that contribute to the problem.

Step 7 —Identify root causes

Analyse the potential causes and identify the root causes —the underlying issues directly responsible for the problem. These root causes are the key areas where interventions should be focused.

Step 8 —Implement solutions

Once the root causes are identified, develop and implement targeted solutions to address them. 

Step 9 —Evaluate and monitor

After implementing the solutions, evaluate their effectiveness and monitor the impact on the problem.

Real-life example of Ishikawa Fishbone Diagram

Let’s take a look at the power of the Fishbone Diagram with a real-world example.

In a textile factory, there was a recurring issue of fabric defects. The Fishbone Diagram helped the production team identify three main categories: Man, machine, and materials.

By exploring these categories further, they discovered that poorly trained operators (man)were making mistakes during the weaving process.

The machinery (machine) wasn’t maintained up-to-date, and the quality of raw materials (materials) was inconsistent. 

Thanks to this insight, the factory implemented targeted solutions that included:

  •  Training programs
  •  Regular maintenance schedules
  • Improved supplier selection processes

These measures had, as a result, a significant reduction in fabric defects.

Benefits of Fishbone Diagram

Ishikawa Fishbone Diagram boosts operational efficiency and cross-team communication, but when deployed properly, it does much more than that:

It brings a systematic and comprehensive analysis of the problem, making sure potential causes are not overlooked.

It promotes teamwork and collaboration, bringing different perspectives together.

Because of its visual nature, the diagram makes complex relationships between causes and effects easier to understand, fostering effective communication and knowledge sharing.

Ishikawa Fishbone Diagram encourages root cause analysis, helping you address underlying issues rather than just treating symptoms. By identifying and eliminating the causes, you can prevent problems from recurring and improve overall efficiency and productivity.

mlean® & Ishikawa Fishbone Diagram

As factory managers and owners, you know that implementing continuous improvement and problem-solving are vital for success. 

The Ishikawa Fishbone Diagram is a great approach to help you unravel the mysteries behind your manufacturing challenges. 

By visually organising potential causes and exploring how they’re connected, you can make informed decisions and implement targeted solutions that address the root causes of problems.

And if you want to do all of this digitally from one single platform, mlean® Production System (mPS) is the right tool for you.

We developed the most complete and flexible software in the market to help you implement continuous improvement and lean manufacturing digitally.

Our digital tool includes a wide range of applications dealing with shop floor management, standardisation, audits, and much more. 

With our mPS, you can unify your tech stack and get a step closer to Operational Excellence.

Why don’t you book a free demo and see for yourself?

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