Publication date: 10/01/2019

Create a Foldover Design

A foldover design removes the confounding of two-factor interactions and main effects. This is especially useful as a follow-up to saturated or near-saturated fractional factorial or Plackett-Burman designs.

This example creates a foldover design of an 8-run design.

1. Select Help > Sample Data Library and open Design Experiment/Reactor 8 Runs.jmp.

2. Select DOE > Augment Design.

3. Select Percent Reacted and click Y, Response.

4. Select Feed Rate, Catalyst, Stir Rate, Temperature, and Concentration and click X, Factor.

5. Click OK.

6. Select Group new runs into separate block to add a blocking variable to the design.

7. Click Fold Over and then click OK.

In the fold over dialog box, if you select no factors, then all design factors are included in the fold over. If you choose a subset of factors to fold over, the remaining factors are replicates of the original runs.

Figure 6.16 Foldover Design on All Factors 

8. Click Make Table.

Each run in Block 2 can be obtained by changing the factor levels (from low to high or from high to low) of a run from Block 1.

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