If the Effects plots provide evidence of statistically significant effects (supported by the ANOVA results), use the Model Graphs to determine whether the size of the effects are of practical importance. If not, then the process or method is said to be practically robust to changes in the parameters over the ranges studied. Use the Factors Tool to choose the effects you wish to display

The increase in C-Inlet Air Temp brought about a statistically significant decrease in tablet hardness. A low setting of this parameter together with a low setting for D-Spray Rate raises Compressibility to its highest predicted value 17.37 displayed on the left. This suggests tightening the range for factors C and D to toward their higher settings should move the results away from the upper specification limit.

Use Point Prediction to predict whether the extreme settings of the factors identified by the analysis will generate future results unlikely to meet your targets:

For compressibility, low settings of factors C & D take us closest to the edge of failure. However even at these worse case settings, the 95% upper prediction limit 17.79 < 18% upper specification limit for this response.

The predicted results fall within acceptable limits (specification); suggesting that the process is robust over the preferred operational ranges