Katharina Busl, MD 
John Malaty, MD What is a Fishbone Diagram?
The cause and effect diagram, also known as a Fishbone or Ishikawa diagram, is a visual tool used to explore the potential causes of a specific problem. By organizing ideas into logical categories, it helps teams move beyond obvious symptoms to find the underlying factors contributing to an adverse event or workflow inefficiency. Its strength lies in structuring a brainstorming session to ensure a comprehensive and balanced analysis.
While the diagram provides a powerful framework for group thinking, its output is only as good as the input from the team. It is a tool designed to harness and direct expert knowledge, not replace it. The diagram is a starting point for deeper investigation and is no substitute for trained clinical judgment and rigorous data validation.
Creating a Fishbone Diagram
1. Define the Problem (Effect): Clearly articulate the issue to the right at the “head” of the diagram.
2. Identify Major Categories: Group causes into broad categories.
Often-used categories include:
- Manpower (labor)
- Method (care delivery)
- Machine (including facilities, tools, systems, and equipment)
- Materials (items and physical resources use for delivering care)
- Mother Nature (external environmental factors)
- Measurement (Data, metrics, and inspections)
3. Brainstorm Causes: Collaborate with your team to identify possible factors within each category.
4. Analyze and Prioritize: Highlight the most significant causes and prioritize them for action.
5. Validate Findings: Verify with data or observations to ensure accuracy.
Resources
The assets below are designed to quickly get you up to speed. Watch the videos for a dynamic overview of RCA and fishbone diagram concepts.
Root Cause Analysis: An Overview
In this video, Dr. John Malaty discusses Root Cause Analysis (RCA), an interdisciplinary team process used to investigate patient safety events and identify the systemic breakdowns that contributed to them — so that corrective actions can prevent similar events from occurring again. This video is excerpted from the free CME course, Interprofessional Patient Safety and Quality Improvement: Root Cause Analysis.
This video covers:
- What an RCA is and how interdisciplinary teams use it to investigate patient safety events.
- Common sources for identifying events that warrant an RCA, from incident reports to patient and family concerns.
- How to prioritize events, including why “near miss” events deserve serious attention.
- Principles for conducting a productive, blame-free RCA discussion.
A note on process: Successful RCAs focus on systems, not individuals. Seek to understand, not to blame — and stick to the facts.
The Fishbone Diagram
In this brief video, Dr. Katharina Busl explains essential features of the Fishbone Diagram, providing a clear, visual overview of its structure and use as a foundational quality improvement tool. This video is excerpted from the free CME course, Implementing a Change.