See FACTEX8 in the SAS/QC Sample LibraryAn experimenter wants to study the effect of cutting speed (Speed) on the surface finish of a component. He considers testing the components at five levels of cutting speed (100, 125, 150,
175, and 200) and decides to test five components at each level.
The design used is a single-factor completely randomized design with five levels and 25 runs. The following statements generate the required design:
proc factex;
factors Speed / nlev=5;
size design=25;
output out=SurfaceExperiment randomize(713)
Speed nvals=(100 125 150 175 200);
run;
proc print data=SurfaceExperiment;
run;
The RANDOMIZE option in the OUTPUT statement randomizes the run order; the random seed, 713 here, is optional. The design
saved in the data set SurfaceExperiment is displayed in Output 7.1.1.
Output 7.1.1: A Completely Randomized Design
| Obs | Speed |
|---|---|
| 1 | 200 |
| 2 | 175 |
| 3 | 200 |
| 4 | 125 |
| 5 | 100 |
| 6 | 150 |
| 7 | 175 |
| 8 | 125 |
| 9 | 100 |
| 10 | 100 |
| 11 | 100 |
| 12 | 200 |
| 13 | 125 |
| 14 | 125 |
| 15 | 150 |
| 16 | 175 |
| 17 | 175 |
| 18 | 150 |
| 19 | 175 |
| 20 | 150 |
| 21 | 200 |
| 22 | 125 |
| 23 | 200 |
| 24 | 150 |
| 25 | 100 |
If you are working through this example on your computer, you might find a different run order in your output. This is due to the difference in the seed value of the random number generator. You can specify a seed value with the RANDOMIZE option. For syntax, see Randomize Design.