Problems or glitches at the workplace are unavoidable. You might spend days coming up with a foolproof strategy to avoid problems. But as human beings, it’s common to make mistakes when we least expect it. The good thing is that we can learn from them and improve.

Internal and external factors impact business processes in unexpected ways. These factors may be market changes, product failures or even new government policies. As professionals, we should try and stay on top of things to minimize negative effects on long-term goals.

Processes such as product development and quality control can be streamlined with an age-old visualization tool known as the fishbone diagram or Ishikawa diagram. The fishbone diagram was introduced by the Japanese organizational theorist Kaoru Ishikawa in the 1960s as a tool to solve problems in manufacturing processes. The diagram resembles a fish’s skeleton, and that is where it gets its name.

The manufacturing and service industries use the fishbone diagram to visualize and identify the underlying causes of a problem.

Let’s explore the importance and uses of an Ishikawa diagram with the help of examples.

Fishbone Or Ishikawa Diagram

A fishbone diagram is also known as a cause-and-effect diagram because it studies the root causes of a problem. The main purpose of this tool is to minimize any defects or imperfections that may adversely impact the final output. These defects or imperfections are known as variables that affect the quality of the final product or service.

Root causes explain why the problem occurred in the first place. A fishbone diagram is used as part of a ‘Root Cause Analysis’ (RCA) to identify and weed out variables.

You can conduct a fishbone analysis for your manufacturing process to ensure that quality is maintained throughout. For instance, say that you’re manufacturing a new line of refrigerators.

If one refrigerator’s thermostat fails, it can likely interrupt the production line as well as impact your organization’s credibility. This is where you can use this visualization tool to zero-in on possible variables to ensure quality control in the production chain.

It’s easy to make a cause-and-effect diagram. You start by adding the problem or effect at the head of the diagram and move from right to left. Each of the bones or branches represents a cause; they branch out into smaller bones or sub-branches that represent the root causes. This will give you a clearly-defined representation of what you need to analyze to mitigate possible errors.

Root Cause Analysis

One of the biggest challenges you’ll face while preparing your fishbone diagram is establishing the relationship between variables and causes. This means assessing which root cause resulted in the variable that is disturbing your process. Causes can be external like the business environment and market changes, or internal like management and machinery.

In this case, you can use RCA to simplify the process. RCA will help you identify the problem, draw the link between causes and variables and determine the timeframe in which the problem occurred. Industries like manufacturing, IT and telecommunications, and health rely on RCA.

The process involving categorizing causes into groups varies from industry to industry. Here are common industry-wise categories of possible causes:

Manufacturing (8Ms)

  • Method

  • Material

  • Manpower

  • Measurement

  • Machinery

  • Mission

  • Management

  • Maintenance

Product Marketing (8Ps)

  • Product

  • Place

  • Price

  • Promotion

  • People

  • Process

  • Performance

  • Physical Evidence

Service Industry (4Ss)

  • Suppliers

  • Skills

  • Surroundings

  • Systems

Once you’ve determined the categories that are relevant to your business, you can evaluate root causes and find relationships between variables and each cause. This can help you start your fishbone analysis by plotting each cause and variable in the diagram.

How To Define The Problem

At times, it can be hard to define a problem if you’re only looking at the facts laid out in front of you. We’ve seen how getting to the root cause can help you identify what went wrong. Another way to get to the bottom of the problem is by asking multiple ‘whys’.

  • Why did the product fail?

  • Why didn’t the line manager monitor the assembly line?

  • Why hasn’t the assembly line been optimized?

  • Why isn’t the optimization up to standard?

  • Why didn’t the supervisor discuss the shortcomings of the assembly line?

Each of these ‘why questions’ will help you find answers to unexpected problems. The more questions your raise about the process, the easier it’ll be to reach a conclusion. Rather than taking everything at face value, asking ‘why’ will help you approach the problem objectively.

The ‘why questions’ will help you categorize the cause and divide the larger problem into manageable parts or sub-tasks. You’ll look at these smaller parts of a problem and combine them into a whole to see the big picture.

Simplifying the problem-solving process with methods like RCA and ‘why questions’ is particularly useful when you’re overwhelmed with information. You’ll be able to define the causes clearly for your fishbone analysis and plot them on your Ishikawa diagram for a visual representation. It’ll also help you keep up with each sub-task and get everyone on the same page.

If you’re struggling to keep up with deadlines, measuring sub-tasks against a pre-defined timeframe will streamline the process even further. You can learn more about the importance of ‘asking why’ in Harappa Education’s Creating Solutions course.

Drawbacks Of A Fishbone Diagram

Even though a cause-and-effect diagram will help you evaluate the root cause of a problem, it’s not foolproof or easy to design without experience and expertise. Putting together a fishbone diagram requires inputs from multiple people.  Different perspectives bring about different opinions that may be confusing to follow. Here are some limitations of a cause-and-effect diagram:

  1. Finding the relationship between variables and root causes can be challenging because everything seems important and relevant at first glance. Separating the problem areas can be demanding if you’re not an expert in the field.

  1. The second challenge is to base your analysis on the correct causes.  Once you’ve listed the causes on the cause-and-effect diagram, you’re most likely to stick to them through the process. It’s possible that you started by defining the wrong causes which then affects the rest of the assessment.

  1. The third challenge is balancing multiple perspectives and inputs. Team members at various levels of the command chain have a role to play in the process. Each person contributes to the manufacturing process and is accountable for their individual roles. As a result, you get multiple opinions when you finally get down to drawing your cause-and-effect diagram. Reconciling views which are at odds with each other may prove to be a challenge.

You can navigate these challenges with experience and insight. Once you get used to the idea of an Ishikawa diagram and how it can help you solve organizational problems, you’ll learn to approach it from different angles. To minimize errors, it might be useful to engage experts and experienced members of your team.

Problem-solving can be challenging if you don’t know where to start. It may seem like a huge leap, but remember that the first step is the hardest. Once you define the problem and understand the nitty-gritty of where things started to go wrong, you’ll be able to zoom out and look at the bigger picture. This can help your present findings to senior management and take action to address the bottlenecks.

Working in teams will help you brainstorm ideas, ask questions and find solutions to problems you may have been overlooked previously. This is because we tend to form an opinion about something from the get-go. We have a blind spot when it comes to new ways of doing things—simply because it will require us to leave our comfort zones. But when other people are involved, you learn to accept their opinions and arrive at solutions collaboratively.


A fishbone diagram may appear intimidating and have some limitations, but it’s a time-tested tool to solve complex problems by breaking them down into branches and sub-branches. Our Creating Solutions course will teach you methods to approach analysis and problem-solving with an impartial mindset. You’ll learn how to consider multiple perspectives, find solutions by asking ‘whys’ and avoid analytical errors. Get to the root cause of a problem with the right skills and become an expert problem-solver!

Explore our Harappa Diaries section to know more about the topic related to the Solve habit such as Importance of Decision Making, Ethical Decision Making, FMEA & Root Cause Analysis in order to develop your problem solving skills.

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