From Data to Diagnosis,
All in One Platform
Build control charts and capability analyses in seconds. Validate stability, evaluate performance, run MSA, and get AI-powered insights — all within a single, powerful platform.
Build control charts and capability analyses in seconds. Validate stability, evaluate performance, run MSA, and get AI-powered insights— all within a single, powerful platform
Experience the platform
Capability Analysis
Capability Analysis
Instantly view Cp, Cpk, Pp, Ppk, and σ, fully synchronized with your control charts in a single click, and clearly explore process distribution through an intuitive histogram view. Quickly assess process performance and identify capability gaps with confidence. Get AI-powered insights to interpret results and turn metrics into clear, actionable decisions.
Your complete process
analysis workspace
Nine capabilities working together seamlessly
Control Charts
I-MR, X̄-R, X̄-S charts — clean, interactive visualization for fast interpretation and shop-floor communication.
Integrated Spreadsheet
Paste, edit, analyze — works with your own data. Every cell update recalculates limits, rules, and capability in real time.
Rule Violation Checks
Western Electric + Spec limits — automatic detection and clear callouts for rule breaches.
Capability Analysis
Cp, Cpk, Pp, Ppk, σ — standard metrics with production-ready outputs.
MSA
Validate the reliability of your measurement system with a clean MSA workspace.
Personal Dashboard
Personal workspaces to store and monitor what matters to you. Mix control charts and capability analyses in one personalized view.
Share & Collaborate
Share control charts with one click and collaborate. Grant view or edit access so others can review, update, and refine the study together.
AI Enhanced Fishbone
Generate structured cause branches and AI-assisted suggestions tied to your data.
Report Export
Export professional SPC, Capability and MSA reports and insights in just a few clicks—ready for audits, and management reviews.
From the SIGMADESK blog
Articles, tutorials and field notes on SPC, MSA and modern quality engineering.
SPC Control Charts (I-MR, Xbar-R, Xbar-S) Explained - Complete Guide
A practical guide to control charts — from common vs. special cause variation to I-MR, X̄-R and X̄-S charts, control limit formulas, and when to use each one.
Process Capability Analysis: Cp, Cpk, Pp, and Ppk Explained
A practical guide to process capability analysis — understand Cp, Cpk, Pp, and Ppk, the difference between short-term and long-term variation, and why customers require capability studies.
Fishbone Diagram Explained: 6M, Ishikawa, Cause & Effect
A practical guide to the fishbone (Ishikawa) diagram — the 6M categories, how to map cause and effect, and how to run a structured root cause analysis for quality problems.
Frequently asked questions
What is SigmaDesk?
SigmaDesk is free, web-based SPC software and a suite of Six Sigma tools for quality engineers. It brings control charts, process capability analysis, and Measurement System Analysis (MSA) together in one platform — with nothing to install.
How can I create control charts online?
Open SigmaDesk in your browser, paste or upload your subgroup data, and it builds the control chart instantly — no setup required. Control limits are calculated automatically, and Western Electric rule and specification-limit violations are flagged as you edit the data.
Which control charts does SigmaDesk support?
SigmaDesk supports the core variable control charts — I-MR, X̄-R and X̄-S — as well as the attribute control charts np, p, c and u. All of them include automatic Western Electric rule and specification-limit violation detection, so shifts, trends and out-of-control points are flagged as you enter your data.
How can I calculate Cp, Cpk, Pp and Ppk with an online calculator?
Enter your measurement data and specification limits in SigmaDesk’s capability analysis and it calculates Cp, Cpk, Pp, Ppk, sigma level and defect rates automatically, alongside a distribution histogram. Everything runs in your browser, so there is nothing to download or configure.
How can I run a Gage R&R online?
SigmaDesk provides a full Gage R&R (MSA) workspace in the browser. Enter your operators, parts and trials, and it quantifies how much of your total variation comes from the measurement system versus the process — so you can confirm your data is trustworthy before drawing conclusions.
How can I use AI in fishbone analysis?
SigmaDesk’s AI-enhanced fishbone (Ishikawa) diagram generates structured cause branches and suggests likely root causes tied to your problem statement. You start from the classic 6M categories, let the AI accelerate brainstorming, then refine the branches yourself.
Do I need to install anything to use SigmaDesk?
SigmaDesk runs entirely in your browser — there is nothing to install or configure. You can paste or upload your own data and start analyzing in under a minute.
Built by engineers,
for engineers
Developed by engineers with real factory experience in manufacturing.Just modern SPC.