Fishbone Diagram
Ishikawa diagram for visual identification of causes.
PURPOSE
Complex problems often have multiple causes that influence each other and are difficult to untangle. The Fishbone Diagram makes cause-and-effect relationships visually clear and helps teams systematically consider all possible cause categories. It prevents important causes from being overlooked.
HOW TO USE
The team draws the problem as the head of the fishbone diagram and adds main categories as bones, typically: People, Machine, Method, Material, Environment, and Measurement. For each category, possible causes are collected and entered as sub-branches. The identified causes are then prioritized and further investigated.
WHAT IT IS
The Fishbone Diagram, also known as Ishikawa Diagram or Cause-and-Effect Diagram, is a visual analysis tool from quality management. It was developed by Kaoru Ishikawa and presents possible causes of a problem in a fishbone-shaped structure. The diagram uses standardized categories to ensure a complete root cause analysis.
EXAMPLE
Example: In your brewery, the beer has tasted different for three batches, and you need to determine whether it's due to the water, raw materials, equipment, or brewing process. With the Fishbone Diagram, you visualize all possible cause categories and map each deviation. You discover that a new malt supplier is the root cause.
WHEN TO USE
PREREQUISITES
- A clearly phrased problem at the fish head
- Skill: Category facilitation
⚠️ WATCH OUT
- Filling bones becomes an end in itself without prioritization
- Common mistake: Entering symptoms as causes
- Common mistake: Stopping after the diagram
💡 SUCCESS FACTORS
- Deepen top causes with 5 whys and check them with data