ChartSays

A customer audit wants proof that the factory's gauges give the same reading when one part is measured twice. The statistics program that could prove it sits on one laptop in the quality office, and its owner is on holiday. In the browser, ChartSays runs the analysis you pick on an uploaded table and returns a report of charts and figures with a written explanation.

The methods come from Six Sigma, a set of statistical habits factories use to find and cut defects. A gauge study, also called MSA or Gage R&R, shows whether the spread in readings comes from the parts or from the people and tools measuring them. Control charts track a process over time, and capability analysis compares its output with the tolerance on the drawing.

Designed experiments help find which machine settings matter, and the site lists 54 methods in all, up to reliability and forecasting models. Files come in as CSV, XLSX, TSV or TXT up to 200 MB, and reports export to PDF, Word or PowerPoint. Small calculators for Cpk, Gage R&R and control limits work without an account, and the site is in English and Simplified Chinese.

An optional AI explanation of the results is off by default. When someone turns it on, the privacy policy says only column names and summary results go to DeepSeek, an AI provider in China. The data rows themselves stay on ChartSays servers for at most 90 days.