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C Chart Maker

You can easily create a C Chart online here! Simply copy your data into the table and select the measurements.

C Chart Maker

Create a C Chart online

In Statistical Process Control (SPC), a C Chart is a type of control chart used to monitor the count or number of nonconformities or defects in a process per unit of measurement. It is particularly useful when the data being collected consists of discrete counts, such as the number of defects in a batch of products, the number of errors in a document, or the number of customer complaints in a day.

How It Works:

  • Data Collection: The C Chart collects data on the number of nonconformities or defects observed in each sample or unit of measurement.
  • Plotting the Chart: On the C Chart, the counts of nonconformities or defects are plotted over time or by sample number on the horizontal axis.
  • Center Line and Control Limits: A center line is drawn on the chart to represent the average or mean number of nonconformities per sample. Upper and lower control limits are also calculated based on the variability of the counts and are typically set at a certain number of standard deviations from the center line.
  • Interpreting the Chart: When the counts of nonconformities fall within the control limits and show random variation around the center line, it indicates that the process is stable and under statistical control. If any counts fall outside the control limits or if there are non-random patterns or trends in the data, it suggests that the process may be experiencing special causes of variation, which require investigation and corrective action.

The C Chart is commonly used in quality control and process improvement initiatives to monitor the occurrence of defects or nonconformities and to ensure that processes meet specified quality standards. By tracking the count of nonconformities over time, organizations can identify areas for improvement, implement corrective actions, and reduce the overall defect rate in their processes.

Cite DATAtab: DATAtab Team (2025). DATAtab: Online Statistics Calculator. DATAtab e.U. Graz, Austria. URL https://datatab.net

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