Table 3.

Plackett-Burman design for eleven variables.

Runs	Variables and levels
	X1	X2	X3	X4	X5	X6	D1	D2	D3	D4	D5
1	L	H	L	L	L	H	H	H	L	H	H
2	H	L	L	L	H	H	H	L	H	H	L
3	L	L	L	H	H	H	L	H	H	L	H
4	L	L	H	H	H	L	H	H	L	H	L
5	L	H	H	H	L	H	H	L	H	L	L
6	H	H	H	L	H	H	L	H	L	L	L
7	H	H	L	H	H	L	H	L	L	L	H
8	H	L	H	H	L	H	L	L	L	H	H
9	L	H	H	L	H	L	L	L	H	H	H
10	H	H	L	H	L	L	L	H	H	H	L
11	H	L	H	L	L	L	H	H	H	L	H
12	L	L	L	L	L	L	L	L	L	L	L

H, high conc. of the components; L, low conc. of the components; D, dummy variable.