3.
Production
Process Characterization
3.5. Case Studies 3.5.1. Furnace Case Study


Analysis of Variance 
The next step is to confirm our interpretation of the plots in the
previous section by running a nested analysis of variance.


Components of Variance 
From the above analysis of variance table, we can compute the
components of variance. Recall that for this data set we have
2 wafers measured at 4 furnace locations for 21 runs. This leads
to the following set of equations.
571.659 = 2*Var(Furnace Location) + Var(Within) 120.893 = Var(Within)
