SECTION 12.3 Summary

• Attribute control charts are dedicated to the monitoring and control of counting type data in the form of proportions or direct counts.
• A chart is used to monitor sample proportions . However, when monitoring counts over continuous intervals of time, area, or volume and there is no definite limit on the number of counts that can be observed, a chart is considered.
• The interpretation of and charts is very similar to that of variable control charts. The out-of-control signals are also the same.