What is a Fishbone Diagram

Do you know the elements of a fishbone diagram?

Fishbone diagrams (commonly known as Ishikawa diagrams, herringbone diagrams, cause-and-effect diagrams) is a diagram used to identify the cause of an effect or a problem. Its name is derived from its fishbone shape, with the problem at the head of the diagram, and its causes along the spine of the ‘fish’.

So when are fishbone diagrams most commonly used?

  • Identifying the root cause of a problem
  • Identifying why parts of a process aren’t working
  • Conducting a mult-variable analysis of a problem
A quick history lesson…

The fishbone diagram was first developed in the 1920s, but was popularised in the 1960s by Japanese professor Kaoru Ishikawa (which is why the diagram is sometimes referred to as the Ishikawa diagram). A pioneer in quality management, the Ishikawa diagram is now considered a staple in analysing most industrial processes.

Fishbone diagram: the Pros and Cons
Pros Cons
  • Shows all of the potential problems in a system or organisation simultaneously
  • Useful for identifying the root cause of a problem
  • Great visual tool for stakeholder presentations
  • Not as useful for identifying interrelationships between causes
  • May end up being overly-complex
Elements of a fishbone diagram
Fishbone Diagram
  • The problem or effect is located at the ‘head’ of the diagram.
  • The categories are connected to the ‘spine’ of the diagram. In the example above, they are Equipment, Process, People, Materials, Environment, and Management.
  • Primary Causes are connected to the categories horizontally.
  • Secondary Causes are connected to the Primary Causes. Secondary Causes lead to Primary Causes, but do not cause the problem themselves.
The 5 Whys

As mentioned, the fishbone diagram is most commonly used to identify the root cause of a problem. Each identifiable cause can be traced back to a root cause. One such method of tracing is known as the 5 Whys technique. The concept behind the technique is that if you keep questioning why a problem exists, you will eventually get to the root of the problem.

As shown in the diagram in the section above, the causes can be placed into categories. Some of these categories may include:

1. The 5 Ms (used in manufacturing)
  • Man / Mind Power
  • Machine / Equipment
  • Material (Physical materials or information)
  • Method / Process
  • Measurement / Medium
  • Mission / Mother Nature
  • Management
  • Maintenance

*The 5 Ms has been expanded to sometimes include the final three categories. This expanded list is commonly referred to as The 8 Ms.

2. The 8 Ps (used in product marketing)
  • Product / Service
  • Price
  • Place
  • Promotion
  • People / Personnel
  • Process
  • Physical evidence
  • Performance
3. The 4 Ss (used in service industries)
  • Surroundings
  • Suppliers
  • Systems
  • Skills
How to create a fishbone diagram
1. What is the problem?

Identify the problem, and write it at the ‘head’ of the fish. This will be your fishbone diagram’s starting point.

2. What are the factors that are causing the problem?

Identify at least four factors, and draw these branching out of the spine of the diagram.

3. Why?

Question why the factors exist and cause the problem. Try to get at least 5 reasons, based on the 5 Whys principle discussed above, and draw these along the factors.

4. Continue to question the causes.

Soon, you will be able to identify the root causes of each factor, and ultimately the problem itself.

Expert tips:
  • Remember that the goal of the fishbone diagram is to focus on finding the cause of the problem, rather than the symptoms.
  • Space out the diagram so that you can include more factors in it.
  • Keep the 5 Whys principle in mind at all times. This type of focused analysis will help you laser in on the root of the problem.
Examples of fishbone diagrams
Fishbone Diagram Example

In this first example, a resident at a retirement home was injured while being transferred from his wheelchair to the toilet. This fishbone diagram details the causes of the accident, and the factors behind several of them, namely the inadequacies of the retirement home staff and equipment.

Fishbone Diagram Examples

In this second example, a machine in a factory malfunctioned. This fishbone diagram details several design and systematic failures that led to the machine malfunctioning.

MindMaster: Diagrams Made Easy

Whether you are a beginner who has discovered fishbone diagrams for the first time, or a pro who uses them on a regular basis, MindMaster is the go-to diagram creating tool for you. Here’s what you can expect from using MindMaster:

1.Ease of use. Change up your diagram’s color and themes to one that suits you best.

2.Customizability. Create topics, sub-topics, and link them together simply with one click. It really is as easy as 1-2-3.

3.Share it. MindMaster’s Group function enables seamless collaboration between you and your teammates.

Aide from fishbone diagrams, MindMaster is ideal for create a whole host of other useful diagrams, including:

  • Radial map
  • Right map
  • Tree map
  • Org-chart map
  • Fishbone right
  • Fishbone left
  • Horizontal timeline
  • Winding timeline
  • Vertical timeline
  • Circle map
  • Bubble map
  • Sector map

So what are you waiting for? Sign up at MindMaster now and start creating!

Related Articles