Method

Parameter Screening

Space Filling

Custom

Variable Levels

Continuous

Discrete

Categorical

Basic Parameters

Properties and Comments

Modified Extensible Lattice Sequence

Any

You can either accept the default number of runs or enter a different value.

Use this method when the response surface is highly nonlinear. This method is a better space filler than Latin Hypercube. The default number of runs is 1.1*((N+1)*(N+2))/2, where N is the number of input variables.

D-Optimal

Any

You can either accept the default number of runs or enter a different value. You can also select the appropriate regression model.

Use this method when the known goal is to build a regression. This method is also useful when corner coverage is important, and you have problems with input variable constraints.

Fractional Factorial

2 or 3

Select the appropriate resolution.

Resolution indicates the level of accuracy of the interactions.  Interactions should not be used with Resolution III.

Full Factorial

Any

Requires a high number of simulations and is therefore unsuitable for most studies. Total number of runs should be less than 1,000,000.

Plackett Burman

2

You can either click Apply for AutoSelect or select a table using the Design pull-down menu.

Computationally least expensive. Number of points can be 12, 20, 24, 28 or 36. Selecting Autoselect will pick pbdgn12 if N < 12, where N is the number of input variables; pbdgn20 if 12 <= N < 20, etc. Limited to 35 input variables.  Categorical variables must have exactly two levels.

Central Composite Design

5

Use this method when the output responses are known to be quadratic. Limited to 20 input variables.

Box-Behnken

3

You can either click Apply for AutoSelect or select a table using the Design pull-down menu.

Use this method for building quadratic response surfaces if the output responses are known to be quadratic and predictions are not required at the edge of the design space. Number of points can be 13, 25, 41, 49. 57. Selecting Autoselect will pick bbdgn13 if N < 4, where N is the number of input variables; bbdgn25 if N = 4, bbdgn41 if N = 5, etc. Limited to 7 input variables.  Discrete variable must have at least 3 levels.  Categorical variables must have exactly 3 levels.

Latin Hypercube

Any

You can either accept the default number of runs or enter a different value.

Use this method when the response surface is highly nonlinear. The default number of runs is  1.1*((N+1)*(N+2))/2, where N is the number of input variables. You must maintain the value of the random seed in order to get repeatable designs.

Hammersley

Any

You can either accept the default number of runs or enter a different value.

Use this method when the response surface is highly nonlinear. This method is a better space filler than Latin Hypercube. The default number of runs is 1.1*((N+1)*(N+2))/2, where N is the number of input variables.

Taguchi

Varies

You can either choose AutoSelect or a specific design matrix.

The levels of each variable must be set accordingly to ensure compability with a specific design matrix.

User-defined Design

Any

Select the perturb file.

Use this method to create a design matrix using abstract variable levels.

Run Matrix

Any

Select the perturb file.

Use this method to create a design matrix using literal variable values.

None