Five Whys Analysis

Apply Five Whys root cause analysis to investigate issues by iteratively asking "why" to drill from symptoms to root causes.

Description

Iteratively ask "why" to move from surface symptoms to fundamental causes. Identifies systemic issues rather than quick fixes.

Usage

/why [issue_description]

Variables

• ISSUE: Problem or symptom to analyze (default: prompt for input)
• DEPTH: Number of "why" iterations (default: 5, adjust as needed)

Steps

1. State the problem clearly
2. Ask "Why did this happen?" and document the answer
3. For that answer, ask "Why?" again
4. Continue until reaching root cause (usually 5 iterations)
5. Validate by working backwards: root cause → symptom
6. Explore branches if multiple causes emerge
7. Propose solutions addressing root causes, not symptoms

Examples

Example 1: Production Bug

Problem: Users see 500 error on checkout
Why 1: Payment service throws exception
Why 2: Request timeout after 30 seconds
Why 3: Database query takes 45 seconds
Why 4: Missing index on transactions table
Why 5: Index creation wasn't in migration scripts
Root Cause: Migration review process doesn't check query performance

Solution: Add query performance checks to migration PR template

Example 2: CI/CD Pipeline Failures

Problem: E2E tests fail intermittently
Why 1: Race condition in async test setup
Why 2: Test doesn't wait for database seed completion
Why 3: Seed function doesn't return promise
Why 4: TypeScript didn't catch missing return type
Why 5: strict mode not enabled in test config
Root Cause: Inconsistent TypeScript config between src and tests

Solution: Unify TypeScript config, enable strict mode everywhere