NW-ROOT-WHY: Toyota 5 Whys Root Cause Analysis

Wave: CROSS_WAVE Agent: Rex (nw-troubleshooter)

Overview

Systematic root cause analysis using Toyota's 5 Whys with multi-causal investigation and evidence-based validation. Investigates multiple cause branches at each level|validates solutions against all identified root causes.

Agent Invocation

@nw-troubleshooter

Execute *investigate-root-cause for {problem-statement}.

Configuration:

• investigation_depth: 5
• multi_causal: true
• evidence_required: true

Usage: DELIVER Wave Retrospective (Phase 3.5)

When invoked as part of /nw-deliver Phase 3.5, execute in order:

1. Gather Inputs, Read the evolution document, mutation results, git log, roadmap.json, and execution-log.json. Gate: all available inputs loaded.
2. Analyze What Worked Well, Identify practices that succeeded and document why, preserve these. Gate: at least one practice documented with rationale.
3. Analyze What Improved, Identify what worked better than before and why, record as reinforcements. Gate: delta from prior execution captured.
4. Analyze What Worked Badly, Apply 5 Whys root cause analysis to failures; produce actionable fix per root cause. Gate: each failure has a root cause and fix.
5. Analyze What Regressed, Apply 5 Whys to anything worse than before; produce prevention action. Gate: each regression has a root cause and prevention action.
6. Tag Meta-Improvements, Mark any items requiring nWave framework changes as meta-improvements. Gate: all framework-level issues flagged.
7. Append Retrospective, Write retrospective section to evolution document. If clean execution (no skips, no failures, no tooling issues), generate brief summary only. Gate: evolution document updated.

Success Criteria