Plackett Burman (PB)

Screens the maximum number of main effects with the least number of experimental runs in case of two-level factors.

Plackett Burman designs are economical designs, and are efficient in screening when only main effects are of interest. This is because the main effects in a Plackett Burman design are, in general, heavily confounded with two-factor interactions. The Plackett Burman design in 12 runs, for example, may be used for an experiment containing up to 11 factors.
X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11
1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1
2 -1 +1 -1 +1 +1 +1 -1 -1 -1 +1 -1
3 -1 -1 +1 -1 +1 +1 +1 -1 -1 -1 +1
4 +1 -1 -1 +1 -1 +1 +1 +1 -1 -1 -1
5 -1 +1 -1 -1 +1 -1 +1 +1 +1 -1 -1
6 -1 -1 +1 -1 -1 +1 -1 +1 +1 +1 -1
7 -1 -1 -1 +1 -1 -1 +1 -1 +1 +1 +1
8 +1 -1 -1 -1 +1 -1 -1 +1 -1 +1 +1
9 +1 +1 -1 -1 -1 +1 -1 -1 +1 -1 +1
10 +1 +1 +1 -1 -1 -1 +1 -1 -1 +1 -1
11 -1 +1 +1 +1 -1 -1 -1 +1 -1 -1 +1
12 +1 -1 +1 +1 +1 -1 -1 -1 +1 -1 -1

Usability Characteristics

  • Only 2-level variables can be used.
  • The Number of runs is a factor of four.
  • The maximum number of variables you can use is 35.
  • Best suited for problems where the interactions are expected to be minimal and the main effects dominate.
  • Any data in the inclusion matrix is combined with the run data for post-processing. Any run matrix point which is already part of the inclusion data will not be rerun.

Settings

In the Specifications step, Settings tab, change method settings.
Parameter Default Range Description
Design Auto Select
  • Auto Select
  • pbdgn8
  • pbdgn12
  • pbdgn16
  • pbdgn20
  • pbdgn24
  • pbdgn28
  • pbdgn32
  • pbdgn36
Note: pbdgn stands for Plackett Burman design.
 Select the lowest number of runs sufficient to study effects.
Resolution III III Select the resolution.
Number of Runs Dependant upon design selected. 8-36 Number of new designs to be evaluated.
Use Inclusion Matrix Off Off or On Concatenation without duplication between the inclusion and the generated run matrix.