To set lower and upper boundsmain topic see also
To set lower and upper bounds1 In the Create Mixture Design dialog box, click Components.
2 Under Lower, click in the component row for which you want set a lower bound, and type a positive number.
Each lower bound must be less than the corresponding upper bound. The sum of the lower bounds for all the components must be less than the value of Single total or the first value in Multiple totals.
3 Use the arrow key to move to Upper and enter a positive number.
Each upper bound must be greater than the corresponding lower bound. Each upper bound must be less than the value of Single total or the first value in Multiple totals. The sum of the upper bounds for all the components must be greater than the value of Single total or the first value in Multiple totals.
4 Repeat steps 2 and 3 to assign bounds for other components. Click OK.
When you change the default lower or upper bounds of a component, the achievable bounds on the other components may need to be adjusted. See Calculating achievable upper bounds.