Fishbone or Ishikawa Diagrams

Fishbone method is another root cause analysis tool to find out the main cause of a problem. This method is used to brainstorm and categorize the causes. The basic concept of this method was first applied in the 1920s, and is considered one of the seven basic tools of quality control. Other names are Ishikawa diagrams, Cause-and-effect diagrams and Herringbone diagrams. It was created by Kaoru Ishikawa. This technique is basically used for product design and quality defect prevention to identify potential factors causing an overall effect. This process has become the founding father of modern management.

How it works

• Draw a box around the problem and think of it as the head of a fish. 
• Draw a horizontal line from the box to the left side as the fish’s spine. 
• Draw angled vertical lines (bones) from the spine to both top and bottom which will represent the cause categories. 
• Brainstorm and categorize all the potential causes. 
• Draw horizontal lines from the cause lines that will represent the sub-causes. 
• Address the relationships between the causes to identify the root causes. 
• Develop and implement solutions to resolve the root causes. 

Benefits

Helps to diagnose the problem rather than focusing on symptoms 

Helps to separate a problem’s content from its history 

Helps to reach consensus around the problem and its causes 

Helps to identify the most likely reasons behind a problem 

Helps teams to ensure that they have identified the actual cause of the problem 

When to use it: Brainstorming sessions and When a team’s thinking tends to fall into ruts. 

Example

Imagine you receive a blurry photo from a project. This blurry image represents the problem at hand, which you can visualize as the head of a fish. To identify the root causes, you draw its spine and branch out to explore potential factors. These factors could include the photographer’s skill, the camera’s quality, the photo-shooting process, or the environmental conditions during the shoot. Each of these elements can be analyzed to pinpoint the main causes of the issue.

Photographer/user:

• Shaky hands
• Lack of knowledge or experience

Camera/equipment:

• Lens
  • Inappropriate lens
  • Damaged lens
  • Dirty lens
• Sensor
  • Damaged sensor
  • Dirty sensor

Work process:

• Inappropriate focus
• Shutter speed too low
• Protective film/cover not removed
• Any filter applied

Environment:

• Subject moved too quickly
• Too dark or foggy weather

Another similar technique to find out the root cause is 5 whys? To know more about the method click the following button. Thank you.