five-whys

Five Whys

Find root cause by asking why repeatedly. Focus on systems, not blame.

Goal

• Define specific problem.
• Trace cause chain.
• Validate with evidence.
• Identify systemic root cause.
• Recommend fixes that prevent recurrence.

Rules

• Use facts over assumptions.
• Ask one question at a time.
• Stop when cause is actionable and verified.
• Go past five whys if needed.
• Avoid personal blame.
• Complex problems may have multiple chains.

Better question forms

• What was going on when this happened?
• What caused this situation?
• What led to this outcome?
• What were we trying to accomplish?
• What process allowed this?

Flow

1. State problem with metric, date, and scope.
2. Ask why it happened.
3. Answer with evidence.
4. Ask why the answer happened.
5. Continue until root cause is systemic.
6. Verify fixing root cause would prevent recurrence.
7. Propose fixes and success metrics.

Resources

• Toyota Production System
• Taiichi Ohno's Workplace Management
• The Lean Startup - Eric Ries

Output

## Five Whys Analysis

Problem: [specific problem]

## Chain
1. Why? [answer + evidence]
2. Why? [answer + evidence]
3. Why? [answer + evidence]
4. Why? [answer + evidence]
5. Why? [answer + evidence]

## Root Cause
- [systemic cause]

## Fixes
- [highest impact fix]
- [supporting fix]

## Success Metrics
- [metric proving recurrence is reduced]