About QMSBox

Last updated: 2026-10-23

What we do

QMSBox (qmsbox.com) is an online toolbox for manufacturing quality engineers, supplier quality engineers, Six Sigma belts and system auditors. It offers more than 60 tools: process capability (Cp, Cpk, Pp, Ppk, Cmk, Cg/Cgk), SPC control charts (X̄-R, X̄-S, p, np, c, u), measurement system analysis (Gage R&R, bias, linearity, stability, attribute agreement), hypothesis tests and regression, DOE and response surface, reliability (Weibull, reliability block diagrams), plus templates for FMEA, 8D, control plans, PPAP, APQP, A3, audit plans and management review.

Each tool page explains what the tool is, when to use it, the formulas, acceptance criteria, how to use it on this site, a worked example and common questions, so engineers can run a sound analysis in the browser and understand the method behind the result.

Methods and accuracy

Statistical calculations run server-side in Python (NumPy, SciPy) and follow published references, mainly the AIAG SPC and MSA reference manuals, the AIAG & VDA FMEA Handbook, the ISO 22514 series and the NIST/SEMATECH e-Handbook of Statistical Methods. Key tools have been checked against the published examples in those references, such as the AIAG MSA average-and-range Gage R&R example.

No online tool replaces professional judgment. For customer submissions, PPAP or audit evidence, keep your raw data and review results under your own procedures.

Free use and paid options

All explanations are free to read. Each tool can be used for free once per day; for more, you can buy a 24-hour unlimited unlock for a single tool or an annual membership, paid through Afdian (WeChat Pay, Alipay) or Stripe (cards). We never store card details. The site also shows Google AdSense ads to cover running costs.

Data and privacy

Data you enter is used only for that calculation and is not stored, unless you sign in and choose to save an analysis to your account. See the Privacy Policy for details.

Who runs it

QMSBox is built and run by an independent individual developer. It has no investors and does not represent any certification body or consultancy. If you find a calculation problem or an error in an explanation, or want a new tool, please email us.

Contact

Email: [email protected] (we usually reply within 1–2 business days)