Attribute Charts

SPC Software displays p chart with control limits to accommodate varying subgroup size

Attribute Charts are a set of control charts specifically designed for Attributes data (i.e. counts data). Attribute charts monitor the process location and variation over time in a single chart.

The family of Attribute Charts include the:

Np-Chart: for monitoring the number of times a condition occurs, relative to a constant sample size, when each sample can either have this condition, or not have this condition

p-Chart: for monitoring the percent of samples having the condition, relative to either a fixed or varying sample size, when each sample can either have this condition, or not have this condition

c-Chart: for monitoring the number of times a condition occurs, relative to a constant sample size, when each sample can have more than one instance of the condition.

u-Chart: for monitoring the percent of samples having the condition, relative to either a fixed or varying sample size, when each sample can have more than one instance of the condition.