The Fishbone Diagram, also known as Ishikawa Diagram, Herringbone Diagram or Cause-and-Effect Diagrams, is a tool to brainstorm, find root causes and visualise the cause and effect of events that happened in a structured way.
One of the Seven Basic Tools of Quality, the Fishbone Diagram is introduced by Kaoru Ishikawa who pioneered quality management processes in the Kawasaki shipyards, and in the process became one of the founding fathers of modern management.
Advantages of using the Fishbone Diagram include:
- Highly visual tool which can branch potential root causes
- Quick to identify root causes that are found multiple times in the same or different area.
- Allows a single overview all causes in one diagram
Disadvantages of the tool include:
- Complex effects with too many causes might become cluttering
- Interrelationships between causes may not be easily identifiable
How to use the Fishbone Diagram
Step 1: Identify the Effect
To begin using the Fishbone Diagram, the Effect is written on the fish’s head, facing to the right.
Step 2: Brainstorm for Causes
The Causes extend to the left as fishbones towards the tail. They branch off the backbone as Areas, and sub-branches to as many levels required to identify Root Causes.
Causes are brainstormed and generated by constantly asking “Why does this happen?” continuously to generate deeper levels of causes.
Step 3: Analyse and validate
Once as many Areas and Causes as possible are brainstormed, you can analyse and identify Root Causes that are addressable as Action Items or repeated in other Areas of the diagram.
Causes can also be further investigated through fact checking, research or surveys to test if they are really contributing to the Effect.
Try out some Tools and Frameworks I’ve worked on
GdApp is a mobile app for you to input and track your progress and habits, with the objective to gain the analytical insights and visible awareness to change and improve yourself.
Lite Toolkit is for you to use self-improvement and productivity tools like the Wheel of Life, Kanban Board and Retrospective Board without signing up, giving away emails or logging in.
Lite Agile is a framework I have created for the purpose of being light and simple for individuals to adopt the Agile mindset and adapt to change.