safety-RCA-analysis

Root Cause Analysis (RCA)

Overview

Systematic root cause analysis for safety incidents using structured methodologies including 5-Why, Fishbone/Ishikawa diagram, and Fault Tree Analysis. Primary agent: Incident Investigation Specialist.

Triggers

• Safety incident requiring investigation
• Recurring similar incidents identified
• High-severity incident (LTI, fatality)
• Regulatory requirement for investigation

Prerequisites

• Incident details and initial report available
• Evidence collected and witness statements recorded
• Investigation team assembled
• Applicable investigation methodology selected

Steps

Step 1: Incident Description

Document the incident clearly:

• What happened → Sequence of events
• Where it happened → Location and area
• When it happened → Date, time, shift
• Who was involved → Injured persons, witnesses
• Why it matters → Impact (injury severity, damage, environmental)

Step 2: Data Collection

Gather all relevant evidence:

• Photographs of the scene
• Witness statements
• Documentation (permits, training records, procedures)
• Physical evidence
• Equipment and material records

Step 3: Causal Factor Identification

Identify all factors that contributed:

• Direct causes → Immediate events leading to incident
• Contributing factors → Conditions that enabled the incident
• Root causes → Systemic failures that, if corrected, would prevent recurrence

Step 4: RCA Methodology Application

Apply selected analysis method:

5-Why Analysis:

• Start with the problem statement
• Ask "why" iteratively until root cause is identified
• Validate each "why" with evidence
• Typically 5 levels deep, but adjust as needed

Fishbone/Ishikawa Analysis:

• Create main categories: People, Methods, Materials, Equipment, Environment, Management
• Brainstorm potential causes for each category
• Analyse relationships between causes
• Identify most likely root causes

Fault Tree Analysis:

• Define top event (the incident)
• Identify immediate causes with AND/OR gates
• Work downward to basic events
• Calculate probabilities if data available

Step 5: Root Cause Validation

Verify identified root causes:

• Evidence-based → Supported by collected evidence
• Controllable → Organisation can implement corrective actions
• System-level → Addresses systemic failure, not just symptoms
• Recurrence prevention → Correcting this cause prevents similar incidents

Step 6: Corrective Action Recommendations

Generate corrective actions for each root cause:

• Immediate actions → Address immediate danger
• Corrective actions → Fix the root cause
• Preventive actions → Prevent recurrence across similar activities

Success Criteria

• Root cause analysis completed within investigation timeline
• Root causes are evidence-based and systemic
• Corrective actions address identified root causes
• Analysis methodology documented and defensible

Common Pitfalls

1. Blaming individual → Stopping at "worker error" without exploring system causes
2. Insufficient evidence → Root causes not supported by adequate evidence
3. Too many root causes → Over-analysis leads to diffuse corrective actions
4. Missing contributing factors → Focusing only on direct causes, missing systemic issues

Cross-References

• safety-incident-tracking/SKILL.md — Incident tracking source
• safety-CAPA-management/SKILL.md — Corrective action management