Five Whys Plus

Five Whys Plus is an AI Engineering skill for Claude Code, published by tjboudreaux in cc-thinking-skills.

969 stars133 forkson tjboudreaux/cc-thinking-skillsAdded 2026/08/21+1% in starsRepository updated 2026/08/07

agent-skillsai-toolsanthropicclaudeclaude-codecritical-thinkingdecision-makingfirst-principlesmental-modelsproblem-solvingsystems-thinking

Install in seconds

Install Five Whys Plus

Copy Five Whys Plus into your Claude Code skills folder. Run the command in your terminal, or review the source on GitHub before installing.

terminal

npx degit https://github.com/tjboudreaux/cc-thinking-skills/tree/main/skills/thinking-five-whys-plus ~/.claude/skills/thinking-five-whys-plus

Requires Node.js. Downloads this skill only — not the rest of the repository — into your Claude Code skills folder.

Without Node.js

git clone https://github.com/tjboudreaux/cc-thinking-skills.git

Clones the whole repository, then copy the skill’s own directory into your skills folder yourself.

In this catalog

Source file: skills/thinking-five-whys-plus/SKILL.md in tjboudreaux/cc-thinking-skills
Installs to: ~/.claude/skills/thinking-five-whys-plus
Collection: One of 25 skills cataloged from this repository
Category: AI Engineering — 2451 skills

What Five Whys Plus does

Five Whys Plus builds an evidence-linked causal chain from a localized fault to an actionable systemic root. Use it when the proximate cause is known but you need to prevent recurrence and verify which enabling conditions made it possible.

Five Whys Plus is cataloged under AI Engineering on DirSkills. Five Whys Plus comes from a repository tagged agent-skills, ai-tools, anthropic, claude and claude-code.

Documentation

README

Excerpt

Five Whys Plus

Build an evidence-linked causal chain from a known proximate fault to an actionable systemic root, then prescribe a countermeasure that would have blocked it.

When to Use

A fault is already localized to a component, path, or subsystem.
The proximate cause is known, but recurrence or systemic root is not.
Prior symptom-only fixes failed and the failure returned.
You need prevention that addresses why the proximate cause was possible.

When NOT to Use

This is the opening of the README. Read the full README on GitHub.

Frequently asked about Five Whys Plus

What else does tjboudreaux publish alongside Five Whys Plus?
Five Whys Plus is one of 25 skills that DirSkills catalogs from tjboudreaux/cc-thinking-skills, the repository it ships in. Its siblings there include Bounded Rationality, Circle Of Competence and Effectuation. Each one is a separate skill with its own page in this directory, installs the same way Five Whys Plus does, and is maintained by tjboudreaux in that same repository. The rest of the collection is listed on the tjboudreaux/cc-thinking-skills page.
How does Five Whys Plus compare to other AI Engineering skills?
Five Whys Plus ranks #1393 by stars among the 2451 AI Engineering skills in this catalog. The most-starred ones next to it are Architecture Decision Records, AI-First Engineering and Agentic OS. DirSkills ranks by the star count of the repository each skill ships in, so that order reflects how popular those repositories are rather than any review of Five Whys Plus against them. Open each page to compare what they document and how they install.