# The PLAN Procedure

### Three Replications with Four Factors

Suppose you want to determine if the order in which four drugs are given affects the response of a subject. If you have only three subjects to test, you can use the following statements to design the experiment.

```proc plan seed=27371;
factors Replicate=3 ordered Drug=4;
run;
```

These statements produce a design with three replicates of the four levels of the factor `Drug` arranged in random order. The three levels of `Replicate` are arranged in order, as shown in FigureĀ 86.1.

Figure 86.1: Three Replications and Four Factors

The PLAN Procedure

Factor Select Levels Order
Replicate 3 3 Ordered
Drug 4 4 Random

Replicate Drug
1 3 2 4 1
2 1 2 4 3
3 4 1 2 3

You might also want to apply one of four different treatments to each cell of this plan (for example, applying different amounts of each drug). The following additional statements create the output shown in FigureĀ 86.2:

```   factors Replicate=3 ordered Drug=4;
treatments Treatment=4;
run;
```

Figure 86.2: Using the TREATMENTS Statement

The PLAN Procedure

Plot Factors
Factor Select Levels Order
Replicate 3 3 Ordered
Drug 4 4 Random

Treatment Factors
Factor Select Levels Order
Treatment 4 4 Random

Replicate Drug Treatment
1 3 1 2 4 2 1 3 4
2 4 3 2 1 4 1 2 3
3 3 2 4 1 1 4 2 3