Control Chart Calculator for Attributes (Discrete Data)

(Click here if you need control charts for variables)

This wizard computes the Lower and Upper Control Limits (LCL, UCL) and the Center Line (CL) for monitoring the fraction of nonconforming items or number of nonconformities (defects) using p and c control charts .

More about control charts.

The limits are based on taking a set of preliminary samples drawn while the process is known to be in control. The information from these samples is used to estimate the sample fraction nonconforming (p) or the number of nonconformities in a sample unit (c).

Nonconforming items

Nonconformities (defects)

Please supply the following information

Sample size (n) The number of items to be sampled at each time point.

Average number of nonconformities (defects) per inspection unit, or an estimate (c)

The ratio of the number of defects to the number of items in a sample during a time when the process was known to be in control.