Adding constraints to design with discrete factors

[#1]

Hello,

I am trying to add constraints to design with 4 discrete factors (X1,X2,X3,X4), where all the factors have 3 levels. What is the best way to add constraint to specify that three factors (X2,X3,X4) should add up to 97%? I am assuming I'll have to add disallowed combinations script option for this but not sure about the script.

[#2]

Is this a mixture design?

https://www.jmp.com/support/help/en/16.2/?os=mac&source=application&utm_source=helpmenu&utm_medium=a...

[#3]

Adding to @statman's help, know that you can specify the X2, X3, and X4 as Mixture type factors and specify their levels as proportions, not a percent. Then click the red triangle at the top and select Advanced Options > Mixture Sum and enter 0.97.

Also know that while combining mixture and non-mixture factors in the same experiment is possible (and encouraged!), it will put constraints on terms in the model. The constraint of the sum means that some of the terms become confounded and cannot be estimated together.