Specify linear constraints for Create Mixture Design (Extreme Vertices)

Stat > DOE > Mixture > Create Mixture Design > Components > Linear Constraints

In addition to the individual bounds on the components, you can specify up to ten linear constraints on the set of components in an extreme vertices design. For more information, go to How are linear constraints different than component bounds in a mixtures design?.

For example, you need to constrain the wet ingredients (eggs, milk, and oil) of a cake mix so that together they are not less than 40% or are not greater than 60% of the total mixture. If you are willing to allow equal amounts of these three ingredients, you would use the following values for the linear constraint: lower value is 0.4, the upper value is 0.6, and the component coefficients are all 1.

The table below shows examples of linear constraints in a four-component blend.

Condition	Lower	Coefficient A	Coefficient B	Coefficient C	Coefficient D	Upper
A + B > 10 and A + B < 20	10	1	1			20
5A + 3B + 8D < 0.1		5	3		8	0.1
0.5B + 0.8D > 0.9	0.9		0.5	0.8

Specify a coefficient for one or more components, and a value for Lower and/or Upper

Lower: Enter the lower value for the linear constraint.
A, B, C, ...: There is one row for each component in the design. Enter a coefficient for one or more of the components.
Upper: Enter the upper value for the linear constraint.