Problems can occur in any business and may take many different forms. It’s important that you are able to determine the cause of such problems in a timely manner. The only way to ensure this is to make use of a structured approach — and that’s where the fishbone diagram comes in. A fishbone diagram may also be referred to as a cause and effect diagram, an Ishikawa diagram, a Herringbone diagram or an Ishikawa diagram.
What is a fishbone diagram?
A fishbone diagram, also known as the Ishikawa diagram or cause and effect diagram, is a tool used to visualize all the potential causes of a problem in order to discover the root causes. The fishbone diagram helps one group these causes and provides a structure in which to display them. When applied correctly, it ensures that you address the actual cause of the problem and don’t just implement a superficial solution.
The fishbone diagram was given its name due to its resemblance to a fish’s skeleton. Initially popularized in the 1960s as a quality tool by its namesake, Kaoru Ishikawa, it has become an important part of many modern-day systems, including Six Sigma.
When to use a fishbone diagram?
Originally conceived as a tool to aid in problem-solving, the fishbone diagram is far more versatile than just that. For any process or system, the fishbone diagram is able to help you break down all of its contributing factors in a hierarchical manner.
Use cases for the fishbone diagram:
- To analyze a problem statement
- To brainstorm the causes of the problem (root cause analysis)
- To analyze a new design
- Process improvement
- Quality improvement
How to make a fishbone diagram
To show how a fishbone diagram is created, we are going to try to solve the problem of “why the customer churn of a product is so high”. In this example, sales of a software product are doing quite well, but their subscriptions are not being renewed. This indicates that after the initial purchase, users don’t see continued value in the product.
To illustrate the step-by-step fishbone diagram creation process, we will fill in the Miro fishbone diagram template. Let’s get started.
Step 1 – Define the problem
The first step to solving any problem, and the key to a successful fishbone diagram, is to correctly define the problem. In this instance, a product has a high churn rate. When viewing the subscription data, the biggest problem noted was that 40% of users were canceling their subscriptions after the first month.
After discussing the situation internally, it was decided that this was the key metric to improve on, and a goal was set to improve this metric to have no more than 20% of new users cancel their subscriptions after the first month.
When a problem is clearly defined, it is easier to identify causes that affect the metric directly. It also encourages evaluating data to determine whether there is really a problem or not.
The problem you define is used as the output of the fishbone diagram. In this case, the percentage of users canceling their subscription after the first month is above 20%.
Problem definition tips:
- If you are using the fishbone diagram to design a process or increase productivity, it is equally important to correctly define your output. Goals should be objective and achievable.
- You should place the problem on the right side of the diagram. Then you can choose how to fill it in. The idea is that “bones” indicate the impact of the causes. The causes with the biggest impact should be placed closer to the head of the fish, and the causes with the smaller impact should be placed further away. You can choose the right-hand side and develop causes in the space to the left or do it vice versa, but remember the idea about the “bones” impact.
Step 2 – Decide on key categories of causes
Once the problem has been properly defined, one must then decide what areas of the problem or process are key to determining the actual cause. These can be unique for your fishbone or based on a template.
For our example, three possible key areas to consider could be:
- Subscription system
If one starts considering potential causes, most of them would fall within one of these three categories. If you felt marketing had a large impact on your retention figures, you could add that as a fourth area. You can have any number of areas, but for simplicity, limiting yourself to no more than 10 is recommended.
Key area decision tips:
- For many industries, a template is available that already defines these key areas. In manufacturing, the 6 Ms are the most popular. The service and marketing industries make use of the 5 Ss and 8 Ps respectively. These can be used as a starting point for streamlined problem-solving.
Step 3 – Determine the actual causes of the problem
Now that the areas are defined, we go through each one and try to determine all the individual influences that can affect our output. We look at each category and list everything that we can think of, which falls within it.
If we look at the subscription system, some possible causes to investigate are:
- Not enough payment options are offered.
- The payment and registration systems are difficult to navigate.
- Credit cards expire voiding renewal.
- The system doesn’t send out reminders for renewals.
When considering the user, potential causes may be:
- Users don’t understand the full benefit of the software (low perceived value).
- Users are unable to perform basic operations or don’t know how to use all the functions.
- Users experience delays when contacting support.
- Users don’t use the software continuously, only requiring it for a few days at a time.
- Users forget about the product.
Coming to the software itself, potential causes may be:
- The software is unstable, and crashes regularly.
- The software is difficult to use.
- Software installation requires multiple additional plugins to function well.
- Key functionality requires additional subscriptions.
- The software is insecure.
These are just a few potential causes. You should fill your fishbone diagram with as many different causes as you are able to come up with. Not every area of your fishbone needs to have causes listed, though (especially when using a template), and some areas will have more causes than others.
You now have a starting point for your root cause determination. To progress, you need to investigate each cause to establish its actual effect on your output.
Actual cause determination tips:
- Consider running a brainstorming session or laying out a process map to generate better causes for your fishbone diagram.
- Invite other team members in the process to ensure all the potential causes are identified.
- Some causes may have multiple sub-causes. Expand your fishbone diagram in a hierarchical manner to encompass all possible causes.
Step 4 – Using tools to plan the way forward
As mentioned earlier, creating a fishbone diagram does not lead to solutions on its own. Further tools are needed to identify the effect that each cause has on output, and ultimately select the causes you want to control.
A process map is basically a flowchart of a specific system, which shows all of its inputs and outputs. It works best in areas like the manufacturing industry, where you have a clearly defined process, with individual steps that each product goes through.
Process mapping involves looking at each step of the process one by one and listing all the potential influences. In an actual manufacturing environment, this may include being present on the production line and viewing the system, taking notes as you go through the process.
A process map is very effective at ensuring that all steps and influences in a system are considered. By defining a process map, you can clearly identify potential causes and add them to your fishbone diagram.
Brainstorming is a fairly common tool used in modern businesses. Instead of considering all of the factors of a fishbone diagram by yourself, include others in the process. When working alone, one is likely to overlook certain areas and completely miss others.
A brainstorming session should be a clearly defined meeting involving problem role-players. Someone must lead the session, taking note of ideas offered by members of the team, and allowing time to discuss matters that lack consensus.
The key to a successful brainstorming session is balancing a structured meeting while ensuring all relevant topics are discussed. The main output from a brainstorming session would be a list of causes to input into your fishbone diagram.
Make sure once your fishbone diagram is concluded that the following steps are clear to all team members. This may involve delegating tasks to other members and ensuring that clear deadlines are set to allow for follow-up.
Forward planning tips:
- If you’re unsure what causes to investigate, by collaborating with team members, you can develop a cause-and-effect matrix. This way, causes are ranked from most important to least important, based on a team’s experience.
- If you’re interested in addressing the root cause of a problem and not just a symptom, the 5 whys technique can be applied to dive deeper.
Working on a fishbone diagram in a remote team
Fishbone diagrams are more effective when multiple people are involved in their creation. For many who telecommute or work in teams in separate locations, this can be hard to achieve. You can try out Miro online whiteboard for collaborating on a fishbone diagram in real time. You can use the pre-made fishbone diagram template together with integrated video and audio functionality, without the need for additional software.
- Color coding can be used to help differentiate ideas in different groups.
- Use the frame feature to present your fishbone diagram and easily export the results to PDF or jpg format.
For any situation where you need to understand all of the contributing factors, a fishbone diagram can help. Don’t get caught up trying to do something quickly before you understand the whole system. Take the time to prepare a fishbone diagram and ensure that the work you do is going to address the key aspects and add value.