Look at the plot to see the variable settings that optimize the responses.

Response optimizer does not use the data in the worksheet. Instead, Minitab estimates the optimal variable values based on stored models. You must fit a model before you can use the response optimizer. If you want to optimize multiple responses, you must fit a model for each response separately. The optimal values are accurate only if all models represent the true relationships.

For the tire data:

·    Temperature: Increases in temperature moves elasticity closer to its target of 100.0, and increases puncture resistance. Because the importance of puncture resistance (2) is higher than elasticity (1), the overall desirability benefits most from maximizing puncture resistance. However, because overall desirability equals 1, the overall desirability cannot improve given the limits set by this design.

·    Curing Time: Increasing the curing time moves elasticity closer to its target of 100.0, but reduces puncture resistance. Because the importance of puncture resistance (2) is higher than elasticity (1), the optimization settings maximize puncture resistance while keeping elasticity as close to its target as possible. It is not possible to improve on puncture resistance within the limits set by this design.

·    Density: Increasing density moves elasticity farther from its target of 100.0 and decreases puncture resistance, both of which are undesirable. If you could extrapolate the plots to lower values of density, it appears that both elasticity and puncture resistance could be increased simultaneously. This suggests might be worthwhile to experiment with lower density.

For the tire data, the individual desirabilities for the tire data are summarized below:

·    Elasticity has an individual desirability score of 1.0000 because the predicted response for elasticity of 100.0 is equal to the target of 100.

·    Puncture resistance has a perfect desirability score of 1.0000 because the predicted response of 947.8029 exceeds the target of 924.882. The goal for puncture resistance was to maximize; therefore higher values are more desirable.

The composite desirability of 1.0000 is a perfect score and indicates that both responses achieved their ideal settings.