# Nw Root Why

Root cause analysis and debugging

- Repository: https://github.com/nWave-ai/nWave (628 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-09-16
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add nWave-ai/nWave --skill nw-root-why -g -a claude-code -y`
Codex: `npx skills add nWave-ai/nWave --skill nw-root-why -g -a codex -y`
Cursor: `npx skills add nWave-ai/nWave --skill nw-root-why -g -a cursor -y`
Gemini CLI: `npx skills add nWave-ai/nWave --skill nw-root-why -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add nWave-ai/nWave`

## Description

Root cause analysis and debugging

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# 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

The rest: https://github.com/nWave-ai/nWave/blob/HEAD/nWave/skills/nw-root-why/SKILL.md