Pareto Method and Fishbone Diagram Analysis- Assignment Five
Human Fit Systems – CNC GUI Interface
Pareto Method (80/20 Rule)
Overview
The Pareto method is used to identify the most significant factors contributing to system problems. Based on the 80/20 principle, a small number of causes typically account for the majority of issues. In Human Factors Engineering, the Pareto method helps prioritize improvements by focusing on the most impactful usability and ergonomic problems.
HFE Application Example (CNC GUI Interface)
For the CNC GUI system, common user-related issues were identified and categorized:
- Complex interface layout
- Slow system response
- Poor alarm visibility
- Inconsistent navigation
- Small or unclear control elements
- Low contrast display
After evaluating frequency and impact, the analysis shows that:
- Complex interface design
- Slow response time
- Poor alarm visibility
- These top issues account for the majority of usability and safety problems.
Interpretation
The Pareto analysis demonstrates that focusing on a few critical factors can significantly improve system performance.
Key Insight
Improving interface simplicity, system responsiveness, and alarm clarity will address most user-related issues.
Conclusion
The Pareto method provides a structured way to prioritize design improvements. In this case, addressing the top three usability issues can produce the greatest impact on safety, efficiency, and user experience.
Fishbone Diagram (Cause-and-Effect Analysis)
Overview
The fishbone diagram, also known as the Ishikawa diagram, is used to identify root causes of a problem by organizing contributing factors into categories. In Human-Centered Engineering (HCE), this method helps analyze how different system components and human interactions contribute to failures or inefficiencies.
HCE Application Example (CNC GUI Interface)
Problem Statement
Operator errors and inefficiencies when using the CNC GUI interface
Main Cause Categories
1. Human (User Factors)
Contributing factors include:
- Lack of training
- Cognitive overload
- Fatigue
- Misinterpretation of interface
2. Interface (GUI Design)
- Poor layout
- Low contrast
- Small buttons
- Inconsistent navigation
3. System (Technical Factors)
- Slow response time
- System lag
- Inaccurate feedback
4. Process (Workflow)
- Complex task sequences
- Lack of guided workflow
- Inefficient task flow
5. Environment
- Poor lighting conditions
- Noise and distractions
- Workspace limitations
Interpretation
The fishbone diagram reveals that system issues are not caused by a single factor, but by a combination of human, technical, and environmental causes.
Key Insight
Interface design and system responsiveness are the most critical contributors to user errors.
Conclusion
The fishbone method provides a structured way to identify root causes of system problems. By addressing issues across multiple categories, a more comprehensive and effective solution can be achieved.
Overall Summary
Both the Pareto method and fishbone diagram support Human Factors Engineering by:
- Identifying key problem areas
- Prioritizing improvements
- Understanding root causes
- Supporting better system design decisions
Together, these methods help ensure that the CNC GUI interface is optimized for usability, safety, and performance.
Final Summary
Both methods provide a structured approach to problem identification and root cause analysis. By combining frequency-based prioritization from Pareto with the categorical depth of Fishbone, HFE professionals can effectively enhance system usability, safety, and operational excellence professionally.