Consider the following guidelines when you define the design.
The design should have 2 to 10 factors
If you have only one factor, you can use One-Way
ANOVA without defining the design.
You want to model curvature in the response
If you do not have curvature in your response, define a custom factorial design.
The run order should be randomized for data collection
If the worksheet contains a column that contains the run order, you can specify that column when you define the design. Otherwise, you can randomize the design after you define the design with Stat > DOE > Modify Design.