The design region can be defined by selecting the Linear Constraint option in the Linear Constraints panel.
When linear constraints are specified using the Add linear constraints option, the random points that form the basis for the clustering algorithm are uniformly-distributed within the constrained design region. The clustering algorithm uses these points.
Select DOE > Mixture Design.
Click Continue.
Add Linear Constraints, if you have any.
Specify the number of runs you want in the Runs box to the right of the Space Filling button in the Mixture Design Type dialog (Mixture Design Selection Dialog).
Click Space Filling.
Consider a three-factor mixture design with the single linear constraint: . Space Filling Design with One Linear Constraint shows a ternary plot for a 30-run Space Filling design that satisfies this constraint. (For a discussion of ternary plots, see Creating Ternary Plots.) Note that the points fall in the constrained design region and are fairly well spread throughout this region.
Space Filling Design with One Linear Constraint