Ishikawa diagrams

Create fishbone diagrams to represent causes of a specific event or problem

Ishikawa diagrams are used to represent causes of a specific event or problem. They are also known as fishbone diagrams, herringbone diagrams, or cause-and-effect diagrams. The diagram resembles a fish skeleton, with the main problem at the head and the causes branching off from the spine.

This is a new diagram type in Mermaid. Its syntax may evolve in future versions. Use the ishikawa-beta keyword.

Basic Ishikawa diagram

This example analyzes the causes of a blurry photo:

Syntax overview

The structure of an Ishikawa diagram is created using indentation:

1. First line: The event or problem being analyzed
2. Subsequent lines: Causes of the event
3. Indentation: Creates the hierarchical “fishbone” structure

Problem statement

The first line defines the main problem or effect:

ishikawa-beta
    Blurry Photo

Primary causes

Main categories of causes are defined at the first level of indentation:

ishikawa-beta
    Blurry Photo
    Process
    User
    Equipment
    Environment

Secondary causes

Sub-causes are defined by further indentation:

ishikawa-beta
    Blurry Photo
    Process
        Out of focus
        Shutter speed too slow
    User
        Shaky hands

Nested categories

You can create sub-categories using uppercase text and additional indentation:

Common use cases

Ishikawa diagrams are widely used for:

• Quality management: Identifying root causes of defects or quality issues
• Process improvement: Analyzing factors affecting process performance
• Problem-solving: Breaking down complex problems into manageable components
• Risk analysis: Identifying potential causes of failures or incidents
• Brainstorming: Organizing team discussions about problem causes

Example: Website downtime

Here’s an example analyzing causes of website downtime:

Example: Customer complaints

Analyzing causes of customer complaints:

Use uppercase text for sub-category headers to create a clear visual hierarchy in your fishbone diagram.

The fishbone structure is automatically created based on your indentation. Make sure to use consistent spacing (tabs or spaces) throughout your diagram.