Primary goal is to identify and quantify sources of variation

The primary goal of PPC is to identify and quantify
sources of variation. Only by doing this will we be able to define an effective
plan for variation reduction and process improvement. Sometimes, in order
to achieve this goal, we must first build mathematical/statistical models
of our processes. In these models we will identify influential factors
and the responses on which they have an effect. We will use these models
to understand how the sources of variation are influenced by the important
factors. This subsection will review many of the modeling tools we have
at our disposal to accomplish these tasks. In particular, the models covered
in this section are linear models, Analysis of Variance (ANOVA) models
and discrete models.
