How Minitab stores factorial designs

If you want to analyze a design, you must store it in the worksheet. By default, Minitab stores the design. If you want to examine the properties of various designs, such as alias structures before selecting the design you want to store, choose Stat > DOE > Factorial > Create Factorial Design > Options and deselect Store design in worksheet.

Each time you create a design, Minitab reserves and names the following columns:

C1 (StdOrder) stores the standard order.
C2 (RunOrder) stores run order.
C3 (CenterPt or PtType) stores the point type. If you create a 2-level design, Minitab names this column CenterPt. If you create a Plackett-Burman or general full factorial design, Minitab names this column PtType. The codes are: 0 is a center point run and 1 is a corner point.
C4 (Blocks) stores the blocking variable. When the design is not blocked, Minitab sets all column values to 1.
C5- Cn stores the factors/components. Minitab stores each factor in your design in a separate column.

If you name the factors, Minitab displays these names in the worksheet. If you did not provide names, Minitab names the factors alphabetically. After you create the design, you can change the factor names directly in the worksheet or with Modify Design. To open Modify Design, choose Stat > DOE > Modify Design.

If you did not assign factor levels in the Factors sub-dialog box, Minitab stores factor levels in coded form (all factor levels are -1 or +1). If you assigned factor levels, the uncoded levels display in the worksheet. After you create the design, you can change the factor levels with Modify Design.

Important

When you create a design using Create Factorial Design, Minitab stores the appropriate design information in the worksheet. To open Create Factorial Design, choose Stat > DOE > Factorial > Create Factorial Design. Minitab needs this stored information to analyze and plot data. If you want to use Analyze Factorial Design, you must follow certain rules when modifying the design information in the worksheet. If you do not, you may corrupt your design. To open Analyze Factorial Design, choose Stat > DOE > Factorial > Analyze Factorial Design.

If you make changes that corrupt your design, you may still be able to analyze it with Analyze Factorial Design after you use Define Custom Factorial Design. To open Define Custom Factorial Design, choose Stat > DOE > Factorial > Define Custom Factorial Design.