Six Sigma in R
Correct R code for SPC control charts, Cp/Cpk/Pp/Ppk, DPMO, and DMAIC method selection.
Test report
- Verdict
- Tested · Works
- Score
- Tested
- Jul 15, 2026
- Environment
- Claude Code 2.x (agent harness)
- Upstream re-checked
- Aug 10, 2026 · dd1ea05
Ran the exact 'is my process capable' capability-study prompt from the repo's own evals.json twice: the baseline produced one unlabeled Cpk number off sd(x); the skill version, following capability_sigma_level.md, produced Cp/Cpk AND Pp/Ppk with an explicit sigma-estimator caveat, a Shapiro-Wilk normality check, and a saved histogram -- a real completeness gap, not cosmetic. Docked hard on docs: the README's headline benchmark ('30/30', '36/36 vs 34/36') points to an eval-workspace/ directory that does not exist in the shipped repo (404 on raw fetch and absent from the GitHub API file listing).
Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works
- Installs cleanly 5/5
- Triggers reliably 5/5
- Output vs. baseline 9/10
- Docs & honesty 2/5
What Six Sigma in R does
Generates runnable R for Six Sigma / statistical-process-control tasks -- control charts, capability indices, hypothesis tests, ANOVA, and sample-size analysis -- and recommends which technique fits when a user describes a practical problem or DMAIC phase instead of naming a test. Triggers on R + quality/process-control requests, even without the words 'Six Sigma'.
How to install Six Sigma in R
git clone https://github.com/robustagile/six-sigma-in-r-skill.git
mkdir -p ~/.claude/skills
cp -r six-sigma-in-r-skill/skills/six-sigma-r ~/.claude/skills/six-sigma-r
Skills live in ~/.claude/skills/ (global) or .claude/skills/
(per-project). Restart Claude Code after installing.
Commands — how to trigger Six Sigma in R
-
/six-sigma-rCorrect R code for SPC control charts, Cp/Cpk/Pp/Ppk, DPMO, and DMAIC method selection.
It also activates on plain-language prompts like these:
-
Write R code to check if my bolt-torque process is capable, Cpk please -
Build a control chart in R for these process measurements -
Calculate DPMO and sigma level for this defect data in R
Frequently asked questions
- Is the Six Sigma in R skill free?
- Yes. The skill itself is free from robustagile/six-sigma-in-r-skill. SkillProof publishes the install command and an independent test verdict at no cost.
- Does Six Sigma in R work with Claude Code?
- We tested it with Claude Code 2.x (agent harness) on Jul 15, 2026. Verdict: Tested · Works. Ran the exact 'is my process capable' capability-study prompt from the repo's own evals.json twice: the baseline produced one unlabeled Cpk number off sd(x); the skill version, following capability_sigma_level.md, produced Cp/Cpk AND Pp/Ppk with an explicit sigma-estimator caveat, a Shapiro-Wilk normality check, and a saved histogram -- a real completeness gap, not cosmetic. Docked hard on docs: the README's headline benchmark ('30/30', '36/36 vs 34/36') points to an eval-workspace/ directory that does not exist in the shipped repo (404 on raw fetch and absent from the GitHub API file listing).
- What is the Six Sigma in R SkillProof Score?
- 8.4/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 9/10, docs & honesty 2/5.
- How do I install Six Sigma in R?
- Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
- Can I use Six Sigma in R with Cursor, Copilot, Gemini CLI, Codex or other AI tools?
- The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.