A research team wants to screen 9 factors down to a smaller set for further experimentation. The team decides to use a 12-run design with 3 center points. In this design, each main effect is partially aliased with more than one 2-way interaction.
In the first table, the total number of runs shows the number of runs in the Plackett-Burman design plus any center points. For this example, the team chose 12 points and added 3 center points, for a total of 15 runs.
The design table shows the experimental conditions or settings for each of the factors for the design points. For example, in the first run of the experiment, Factors A, B, C, E, F, and H are at the high setting. Factors D, G, and J are at the low setting.
Minitab randomizes the design by default, so if you replicate this example your run order will not match the order in the example output.
Factors: | 9 | Replicates: | 1 |
---|---|---|---|
Base runs: | 15 | Total runs: | 15 |
Base blocks: | 1 | Total blocks: | 1 |
Run | Blk | A | B | C | D | E | F | G | H | J |
---|---|---|---|---|---|---|---|---|---|---|
1 | 1 | + | + | + | - | + | + | - | + | - |
2 | 1 | + | - | + | - | - | - | + | + | + |
3 | 1 | - | - | + | + | + | - | + | + | - |
4 | 1 | + | - | + | + | - | + | - | - | - |
5 | 1 | - | + | - | - | - | + | + | + | - |
6 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
7 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
8 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
9 | 1 | - | - | - | - | - | - | - | - | - |
10 | 1 | - | - | - | + | + | + | - | + | + |
11 | 1 | - | + | + | + | - | + | + | - | + |
12 | 1 | + | + | - | + | + | - | + | - | - |
13 | 1 | - | + | + | - | + | - | - | - | + |
14 | 1 | + | - | - | - | + | + | + | - | + |
15 | 1 | + | + | - | + | - | - | - | + | + |