2n-k

Fractional Factorial

+

Star points

+

Centerpoints

nstructionfor K factors

–

Selecta resolutionVtwo-levelfractional factorial for K factors

–

Generate2 x K star points

α o o ...........
–α o o ...........
o α o ...........
o -α o ...........

o

o

o

o

.

.

.

o

o

o ...........

α

o

o

o ..........-α

whereα4= m and m = number of runs in the two-level fractional factorial.

•

Add one or more centerpoints, i.e.,

o

o

o

.

.

.

.

.

o

RUN

1

2

3

4

5

6

7

8

9

X1

–

+

–

+

1.414

-1.414

0

0

0

X2

–

–

+

+

0

0

1.414

-1.414

0