SPC and the measurement process

This paper presents the basic principles of SPC charts and how to employ SPC techniques in performing simple measurement accuracy and precision studies. Information on the concepts of variation, basic statistics, the normal distribution, and the central limit theorem are presented to set the foundation for SPC. With these concepts in place, it is possible to introduce the two SPC charts on which accuracy and precision studies can be based—individuals charts and X‐bar charts. Many other types of control charts exist that are not described in this paper, specifically, control charts for attributes data. These are generally not applicable to measurement accuracy and precision studies, and numerous texts are available that sufficiently detail control charts for attributes data.