np-Chart

Attribute control chart monitoring the count of nonconforming units when sample size is constant.

Examples

01The final inspection tracks an np-Chart of rejected units in each fixed sample of 200 bottles.
02At the quarterly meeting, the np-Chart from the supplier's packaging line shows a stable process at about 3 rejects per 200 units.
03When the np-Chart shows 12 rejects against an upper limit of 9, the line is checked for a worn capping head.