This example shows you how to construct a design that includes covariate information. You want to model the Shrinkage of parts produced by an injection molding process. You have 25 batches of material for which measurements of Specific Gravity and Tensile Strength are available, as well as a Supplier identification.You want to study the effects of three controllable factors, Temperature (mold temperature), Speed (screw speed), and Time (hold time), on Shrinkage. But you also want to include the effects of the covariates.
