ABSTRACT
This chapter introduces the basic ideas behind process capability analysis. It defines the most important metrics for measuring quality: the proportion of nonconforming items, % yield, DPM, DPMO, and the sigma quality level. The use of process capability analysis in Six Sigma programs is discussed. The chapter also presents two sample datasets that will be used throughout the book, one consisting of variable data and the other consisting of attribute data. Methods for summarizing data are presented, both numerical and graphical. Summary statistics are introduced for measuring location, variability, and shape. Graphical methods include frequency histograms, box-and-whisker plots, and smoothed scatterplots.
