Fishbone Diagram

Irrespective of the business domain, problems can occur in any business in various forms. So, in the initial phase of the business, when something goes wrong, it’s vital to understand the root cause of the issue to prevent it from happening further. However, at times, it becomes difficult to identify the underlying root cause of the issue. Having a structured approach can help overcome this issue in such a scenario. Hence, there comes the concept of the “Fishbone diagram.”

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Fishbone Diagram – Definition!

Fishbone Diagram is well known as the “Cause and Effect diagram” or” Ishikawa diagram.”

Ishikawa diagram is named after an organizational therapist, a quality management innovator, and an engineering professor at the University of Tokyo, kauoru Ishikawa, in 1960.

“A Fishbone diagram is defined as a visual tool designed for the team to identify the potential cause of the issue and move on to a solution.”

The Fishbone diagram is initially known as a quality tool.

It recognizes, analyses, and improves the quality issues.

The Fishbone diagram considers its skeleton structure with the potential cause branching out from the spine. Here, each branch is a category.

Due to its popularity, the Fishbone diagram has become one of the most popular tools in Six Sigma.

Components of a Fishbone Diagram

From the name, it can be understood that it has the structure of a fish’s bone. The diagram has a structure of a fish that is facing towards the right side.

Fish head – The head of the fish denotes the main problem to be solved.

Bones of the skeleton – The cause of the identified problem is the bone of the fish’s skeleton. The ribs and branches in the skeleton denote the major causes.

Types of Fishbone Diagrams

Professionals who are into quality management can use fishbone diagrams that help them brainstorm the root cause of the issue. In addition, various industries use fishbone diagrams. Thus, here are a few types of fishbone diagrams that you should be aware of:

  • Simple fishbone diagram
  • 4S fishbone diagram
  • 8P fishbone diagram
  • 5M/1E fishbone diagram

Simple Fishbone Diagram

It is one of the most basic and flexible forms of a fishbone diagram. It doesn’t have any predetermined categories. You can create affinities/categories unique to your organization. Irrespective of team and domain, you can use it for various purposes.

Since these diagrams are simple and flexible, there is no need for technical knowledge to work on them. With the help of simple tools available for drawing, a simple fishbone diagram can be drawn. It doesn’t rely on any rules or functions to be followed and can be used for any problem.

For example, A health care organization’s affinities are quite different from that of a manufacturer and vice versa.

The 4S Fishbone Diagram

The 4S diagram is more often is used in a service-oriented organization. The name is derived from how the information about potential causes is organized. Here, the causes are classified into four categories: systems, surroundings, skills, and suppliers.

In most cases, this type of fishbone diagram can be applied to the service type industry. For manufacturing of other types of industries, the internal services can use the 4S fishbone diagram to resolve the problem. The causes related to the 4S, namely systems, surroundings, skills, and suppliers, could be identified and resolved.

Though it is commonly used in the service industry, it could also be used in other industries.

The 8P Fishbone Diagram

The 8P fishbone diagram is quite popular in the service and administrative industry. This type of fishbone is named after eight categories. They are Price, People, Processes, Policies, Promotion, Place, Physical location, and Product.

This fishbone diagram deals with service and administration; hence, any industry involving administration can use it. The prime advantage of using this diagram is that it identifies various reasons or causes of the main problem. There are eight P’s in the diagram that helps in identifying the root cause of the problem. Four P’s are in the top of the bone and the other 4 P’s are in the bottom of the bone.

5M/ 1E Fishbone Diagram

This category of the fishbone diagram is more applicable in the manufacturing industry. The teams using this fishbone include six categories: Machine, Methods, Measurements, Manpower, Materials, and Environment. These six categories cover every aspect we come across in the manufacturing sector. An additional two categories are- Maintenance and Money.

With the help of these 5Ms and 1E, the potential causes related to the problem could be identified easily. However, since it mainly deals with the manufacturing sector-related factors, it can only be used. Other fields can use this type if applied.

Thus, the above mentioned are some of the categories we can have with the Fishbone diagram. Here, the main aim is to choose the one considering your requirement. And most importantly, you can also opt for customization for your situation, the amount of time required to accomplish the task, and the causes that could arise.

Tips for Conducting a Brainstorming Session

The first step while creating a fishbone diagram is the “brainstorming” process.

When using a fishbone diagram, it’s important to monitor your team’s brainstorming ability. Here are a few tips to start with the brainstorming process.

  • Provide multiple options for the employees to contribute their ideas. For example: Use sticky notes or start brainstorming in small groups initially
  • Give ample time for the employee to get ready for the session. You can consider it as priming their minds for the session
  • Stick on to the concept of “no idea is also a bad idea. “If one is not acceptable, it discourages others from giving an idea they are not 100% sure of
  • You can invite the right people to the session, even outside your team

Steps to Construct a Fishbone Diagram

Fishbone diagrams are easy to create, use, and understand its various aspects. So, here we shall understand how to start with the process:

Team Gathering

If you want to figure out the root cause of the issue, using the Fishbone diagram is best. With more people involved in the process, you will have more perspectives on the problem. One of the major benefits of having a bigger team is looking for suggestions from the senior members of every department/domain.

Define the Problem Statement

The next step is to define the problem clearly and ensure that all the team members agree to the defined statement. Defining the problem statement includes what it is all about, how it occurred, and when. This process makes it simpler to think about the root cause of the problem.

Write the problem statement at the head of the fish so that your team can work towards the problem. As the next step, draw a line towards the fish head, which becomes the fish’s backbone. 

Create Categories

As the next step in the process, brainstorm all the categories. And connect these categories to the fish’s backbone, i.e., ribs. Again, you can use as many categories to describe the issue.

Contributing Aspects

The next step includes brainstorming all the possible causes and allotting each cause to a specific rib. It is indeed very helpful for your team to proceed without any hindrance. Keep adding all the causes to the rib until you have all the possible causes in your hand.

It has to be noted here that every contributing factor may or may not fit into a single category. If you come across contributing causes that fit into multiple categories, place them in their specific places and look for changes in the output.

Analyze and Look for the Deeper Cause

You might come across multiple branches of smaller ribs. For example, it indicates a lack of expertise, training, and not having suitable people for a job role. Consider all these factors as mini-crib and dig out the reason for its repeated occurrence with a thorough understanding. Though the process seems time-consuming, it’s vital to have a comprehensive understanding and know when to stop the issue from a repeated occurrence.

Fix the Issue

When the cause of the issue is identifiable and controllable, remove it from the rib at the earliest. And ensure that it doesn’t occur again.

Advantages of Fishbone Diagram

Projects will not always be successful and moving in the right direction. There are chances of arising new issues while working on the project, which may cause serious problems. To overcome those problems, the root cause for the issues has to be identified and analyzed. For identifying and analyzing things, the fishbone diagram is highly useful. For overcoming the identified problems, there may be several ideas from team members. The ideas can be sorted out into categories, and their relationships are defined with the fishbone diagram. Therefore, a fishbone diagram is highly recommended to understand the root cause and its effects.

If you want to uncover the root cause of an issue and address it appreciably, then using a fishbone diagram is the best tool that you will have to consider. Let us know more about the benefits of this tool:

Simple and Effective Visualization

A fishbone diagram is an effective visualization tool that helps you identify the issues. Since the tool is visually connected, you can easily identify the root cause of the issue and take necessary actions to rectify it.

Prioritize the Team Focus

The fishbone diagram helps the team stay focused while discussing the issues and the necessary steps to resolve them. Moreover, it also ensures that none of the team members waste their time working the issues that won’t even exist.

Scope for Improvement

And the previous point brings us to our next aspect. Since all the processes are visualized here, you can easily look for certain improvements in the processes. Though you can accomplish this task with the help of other tools, using a fishbone diagram has unique benefits in this relation. Using this tool over multiple iterations will help you analyze how the change affects the other processes.

Involves the Team in the Brainstorming Process

One of the major benefits of using a fishbone diagram is it facilitates the brainstorming process. It structures the team to brainstorm about the root cause of the issue to get a specific output.

Identify the Issues Easily

The tool also helps you identify the issues in the process much easier, which is essential for in-depth analysis. Therefore, the Fishbone diagram is quite a useful tool for identifying the issues and necessary solutions for the stakeholders.

Enhances Teams Understanding

Using a fishbone diagram ensures that everyone in the team stays on the same page. Nevertheless, it has become a common reason to implement in most quality-oriented organizations. If the organization/team is facing any issue relating to analyzing the issue and keeping up with the pace, this tool is a must-go.

Disadvantages of Fishbone diagram

Now let’s look at some of the disadvantages of using a fishbone diagram.

  • The brainstorming process will lead to the occurrence of the various potential root causes of the issues, including relevant and irrelevant. It results in investing more time and leads to confusion as well.
  • The fishbone diagram leads to a divergent approach, wherein you would want to fix every root cause that leads to the major issue. Unfortunately, every team in the organization doesn’t have ample resources to fix every potential root cause, leading to a lower success rate. Unable to resolve the issue, feels like the problem is quite a huge task.
  • The multiple contributing factors in the diagram make it a mess, which is quite tedious to understand.

When to Use a Fishbone Diagram?

Initially, the fishbone diagram as a tool to resolve the problem-solving issue. Irrespective of the system/process, the fishbone diagram will assist you in breakdown all the contributing factors in a hierarchical process.

It is a well-known fact that the fishbone diagram helps the projects and associated team to progress towards success. For example, when a team hits a roadblock and cannot identify the cause leading to the issue, you may need to look deeper into the underlying issues. Using a fishbone diagram will encourage the team to identify issues they weren’t even aware of in such a scenario. 

The Fishbone diagram was originally developed as a quality control tool. You can find it useful in the following cases:

  • To analyze a complex issue with various causes
  • When required, a different point of view for a problem
  • To focus on problem-solving aspects
  • Uncover all the issues and identify why a process is not working as expected
  • Planning to improve the thinking criteria when traditional ways are time-consuming
  • Implementing it on seven basic tools of qualitative methodology

We also covered more on the fishbone diagram in our previous blog; take a glance at it, “How to Use the Fishbone Diagrams for Root Cause Analysis.”

Use Case

A customer comes up with an issue with the product that has passed through quality control. Thus, a quality assurance investigation reveals a machine error causing the defect. But, unfortunately, quality-control tests and other related processes failed to detect the issue in the initial phase. And it took three days for a customer service representative to resolve the issue.

It has been identified that a product that passed through quality control has had issues. To overcome this, the root cause of the issue has to be analyzed. Here comes the fishbone diagram. While applying the fishbone diagram of any type related to manufacturing, a solution can be attained. The major causes that are related to the issue are identified in the diagram. In this way, one can easily solve the issue identified in a project or a product using a fishbone diagram.


A Fishbone diagram is a simple tool for visualizing cause and effect relationships. With the continuous implementation of this tool, the organization can address the issue quickly and accurately. Organizations can effectively use it to attain six-sigma results in their business processes.

Creating a fishbone diagram in collaboration with cross-functional teams develops trust amongst the employees, enhances knowledge, and provides a thorough understanding of the process. In addition, it helps to focus on defect reduction and process improvement. 

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