Interpret the key results for Create Plackett-Burman Design

Use the summary of the design to examine the key design properties. Most properties of the design match selections that you made for the base design during design creation. The number of runs differs from the number of runs in the base design when the design includes any of these elements:

Replicates: Each replicate adds runs equal to the number of corner points and center points in the base design.
Center points: Each center point adds 1 to the number of runs in the base design.
Text factors and center points: Minitab adds center points at each level of a text factor in a 2-level design. Thus, each text factor doubles the number of center points in the design.

Design Summary

Factors:	9	Replicates:	1
Base runs:	12	Total runs:	12
Base blocks:	1	Total blocks:	1

Key output: Design summary

In these results, all of the design characteristics are the same as selections made during the creation of the design.

Design Summary

Factors:	9	Replicates:	2
Base runs:	16	Total runs:	32
Base blocks:	1	Total blocks:	1

Center points: 8

* NOTE * The number of center points specified is doubled for each categorical factor. For Q
categorical factors, the result is 2^Q times as many center points.

These results show a design with 2 replicates, 2 center points per replicate, and 1 text factor. The base number of runs includes 12 Plackett-Burman runs and the center points. Because design includes 2 center points per replicate and the design includes a text factor, the design has 4 center points per replicate. Thus, the number of runs in the base design is 16. With 2 replicates, the total number of runs is 32.