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What is a Fishbone Diagram? (or Ishikawa Diagram)

A Fishbone Diagram template (also known as a cause-and-effect diagram or Ishikawa Diagram) is an important LEAN tool that can be used in Excel to help brainstorm, identify potential causes, and sort ideas into useful categories. A fishbone diagram can be used to visually see cause and effect. This method is more structured than other tools for brainstorming the causes of a problem, such as the Five Whys tool. The head or mouth of the fish displays the problem or effect. The smaller “bones”, which are part of the various cause categories, list possible contributing causes. A fishbone diagram is a useful tool for identifying the potential causes of a problem. It allows the team to examine the distinct categories and consider alternative causes. Team members with personal knowledge of the systems and processes involved in the event or problem should be included.

Kaoru Ishikawa, who was trying to solve problems at Kawasaki shipyards during the 1960s, revived the fishbone diagram idea and it quickly became popular. The fishbone diagram was not new even in the 1960s. It was used as a quality control tool in the 1920s.

Variation is the enemy

Variation is your enemy when it comes to quality or efficiency. No matter what your business is, it’s important to not leave anything to chance. A predictable process should begin from the moment your client contacts us. The goal is customer satisfaction. Variation in the process can lead to variation in the product.

Fishbone diagrams can help you identify the variables that could be involved in the equation. These diagrams allow you to plan your projects so you can deal with them in a way that ensures that your final product meets your expectations.

How to make a Fishbone Diagram?

What are the elements of a fishbone diagram?
What are the elements of a fishbone diagram?

The diagram is structured like a fishbone, with the “head” representing the problem or effect you’re trying to analyze, and the “bones” branching off as categories or major factors that could contribute to that problem. These categories are often predefined and can vary based on the nature of the problem, but commonly include:

  • Methods: Procedures, policies, or processes involved.
  • Machines: Equipment, tools, or technology used.
  • Materials: Substances, components, or resources utilized.
  • Manpower: People involved, including skills and training.
  • Measurement: Metrics, data, or methods used for evaluation.
  • Environment: Surrounding conditions or external factors.

These six categories can be used to create your fishbone diagram. You can indicate sub-factors by attaching mini-fish bones to the line.

Steps to create a Fishbone Diagram

The primary purpose of the fishbone diagram, often created using a fishbone template Excel, is to visually map out various potential causes of a problem in a structured manner, facilitating a comprehensive understanding of the root causes. It’s commonly used in quality management, problem-solving methodologies like Six Sigma, process improvement initiatives, and brainstorming sessions to identify and prioritize causes for further investigation and resolution.

How to create a Fishbone template in Excel?
How to create a Fishbone template in Excel?

Step 1: Define the Problem

Clearly identify and define the problem or effect you want to investigate. Write it down as the “head” of the fishbone diagram. Be specific about the issue and its impact.

Step 2: Drawing the Backbone

The head of the fish represents the “Effect” (or the Problem in which we are trying to find the root cause). The bones coming off the main backbone are high-level “Causes” that branch off to sub-causes and potentially to root causes.

  • Create the head of the fishbone diagram template in Excel which lists the problem or issue to be investigated. Be specific about how and when the problem occurs.
  • Create a backbone for the fish (a straight line that leads to the head).
  • Create a horizontal line leading from the problem statement. This line represents the backbone of the fishbone diagram.
  • Label the starting point as “Main Causes” or a suitable title.

Step 3: Drawing the Main Bones (the Main Causes)

In the Fishbone Diagram template in Excel or Ishikawa Diagram that you already did, we draw the main bones that come off the backbone. There are two separate ways we can categorize these bones:

  • These bones could be the main causes of the effect (or problem) which we can drill down further to discover root causes.
  • We can use generic categorizations (like the ones below).
    • Methods (for example, SOP’s, work instructions, OJT).
    • Machines (or equipment, databases, IT assets).
    • People (labor or manpower).
    • Materials (actual materials or information).
    • Measurement (for example KPIs, exception reports, production expectancies).
    • Environment (for example noise, temperature, culture).
  • Branching off from the backbone, draw several lines (resembling bones) perpendicular to represent major categories of causes.
  • Commonly used categories include Methods, Machines, People, Materials, Measurement, and Environment (or you can use categories specific to your problem).

Step 4: Brainstorm and List the Causes

  • Under each category, list potential causes or contributing factors related to the problem.
  • Encourage brainstorming and input from a team to gather diverse perspectives.

Explore Sub-Causes (if needed)

  • For each main cause listed, delve deeper by identifying sub-causes or factors that contribute to the main cause. Continue to branch out these sub-causes from the main causes.

Step 5: Analyze and Prioritize Causes

  • Assess the listed causes and identify which ones are most likely contributing significantly to the problem.
  • Prioritize causes based on their impact and relevance to the problem.

Ask “Why?” Repeatedly:

  • To reach the root cause(s), ask “Why does this cause happen?” for each identified cause or sub-cause. Keep asking “Why?” to dig deeper until you reach fundamental issues. We keep asking “Why do the contributing causes happen?” to dig deeper into the potential root causes.

Step 6: Identify Actionable Root Causes

It is especially important in the “Fishbone Diagram” or “Ishikawa Diagram” that the potential root causes are ACTIONABLE ITEMS! Actionable items are problems that we can implement a tangible fix. For example, one of the root causes of the effect of “Employees are an average of 7 minutes late to work over a 30-day period” is that the metric of “on-time” has not been defined in the employee handbook. The fix to this is tangible (to define “on time” and subsequently to measure timeliness).

  • Focus on root causes that are actionable and can be addressed or fixed.
  • Ensure these root causes are specific and tangible, allowing for the implementation of effective solutions.

Step 7: Document and Communicate Findings

  • Record the fishbone diagram and its findings for reference and further analysis.
  • Communicate the identified causes and potential solutions to stakeholders or relevant team members.
How to make a fishbone diagram?
How to make a fishbone diagram?

When to Use a Fishbone Diagram?

A fishbone diagram, also known as an Ishikawa diagram or a cause-and-effect diagram, is a versatile tool used in various situations where identifying the root causes of a problem or effect is essential, often supported by a fishbone template Excel. Here are some scenarios when a fishbone diagram can be beneficial:

  • Problem Solving: It’s commonly used in problem-solving processes to analyze and identify the causes of a specific issue, allowing teams to address the underlying factors rather than just symptoms.
  • Quality Improvement: In industries like manufacturing, healthcare, and service sectors, the fishbone diagram helps identify factors affecting quality issues, facilitating improvement initiatives.
  • Process Improvement: When analyzing workflows or processes, the diagram helps pinpoint bottlenecks or inefficiencies by identifying the causes impacting the process flow.
  • Product Development: During product design or development phases, it helps recognize potential issues and their causes before they become significant problems in the final product.
  • Root Cause Analysis: It’s useful in conducting root cause analysis to identify underlying reasons for accidents, failures, errors, or non-conformances in various fields.
  • Team Collaboration: It encourages collaboration among team members by providing a visual representation of different perspectives, and fostering brainstorming sessions to identify causes collectively.
  • Decision Making: It assists in decision-making processes by systematically analyzing multiple potential causes, helping teams make informed decisions based on a comprehensive understanding of the issue.
  • Project Management: In project management, aids in risk assessment, enabling teams to foresee potential issues and plan mitigation strategies.
  • Training and Education: It’s an effective educational tool to teach problem-solving techniques and critical thinking by breaking down complex problems into their causes.
  • Continuous Improvement Initiatives: It supports continuous improvement efforts by continuously analyzing and addressing root causes, promoting a culture of ongoing improvement within organizations.

Overall, the fishbone diagram is a versatile tool applicable across various industries and scenarios where a systematic analysis of causes and effects is required to address problems, improve processes, and drive effective solutions.