root-cause-analyzer

// Systematic root cause identification skill with 5 Whys, fishbone diagrams, fault tree analysis, and hypothesis testing

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updated:March 4, 2026

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SKILL.md Frontmatter

nameroot-cause-analyzer

descriptionSystematic root cause identification skill with 5 Whys, fishbone diagrams, fault tree analysis, and hypothesis testing

allowed-toolsRead,Write,Glob,Grep,Edit

metadata[object Object]

Root Cause Analyzer

Overview

The Root Cause Analyzer skill provides comprehensive capabilities for systematic root cause identification and verification. It supports multiple analysis methods including 5 Whys, Ishikawa diagrams, fault tree analysis, and statistical hypothesis testing.

Capabilities

5 Whys facilitation
Ishikawa (fishbone) diagram creation
Fault tree analysis (FTA)
Hypothesis formulation
Chi-square testing
Correlation analysis
Pareto chart generation
Root cause verification

Used By Processes

SIX-005: Root Cause Analysis
QMS-005: FMEA Facilitation
CI-002: A3 Problem Solving

Tools and Libraries

Cause analysis tools
Statistical testing libraries
Visualization platforms
Collaboration tools

Usage

skill: root-cause-analyzer
inputs:
  problem_statement: "25% increase in customer complaints for product X"
  analysis_method: "fishbone"  # 5_whys | fishbone | fta | is_is_not
  data:
    defect_counts_by_category:
      materials: 45
      methods: 23
      machines: 67
      manpower: 12
      measurement: 8
      environment: 5
  hypothesis_to_test: "Machine wear is causing increased defects"
outputs:
  - root_cause_diagram
  - potential_causes
  - verified_root_causes
  - pareto_analysis
  - statistical_verification
  - recommendations

Analysis Methods

5 Whys

Ask "Why?" iteratively to drill down to root cause:

Why did the problem occur?
Why did that happen?
Why did that happen?
Why did that happen?
Why did that happen?

Ishikawa (Fishbone) Categories

Man (Manpower) - Training, skills, fatigue
Machine - Equipment, tools, technology
Method - Procedures, processes, policies
Material - Raw materials, consumables
Measurement - Inspection, calibration
Mother Nature (Environment) - Temperature, humidity, conditions

Fault Tree Analysis

Top event (undesired outcome)
AND gates (all inputs required)
OR gates (any input sufficient)
Basic events (root causes)

Verification Techniques

Technique	Use Case
Chi-square test	Categorical data relationships
Correlation analysis	Continuous variable relationships
Regression	Predictive relationships
Designed experiments	Controlled cause-effect testing
Pareto analysis	Vital few vs. trivial many

Integration Points

Quality Management Systems
Corrective action systems
Statistical analysis tools
Knowledge management systems