Storing the design
main topic 

If you want to analyze a design, you must store it in the worksheet. By default, Minitab stores the design. If you want to see the properties of various designs, such as alias structures before selecting the design you want to store, uncheck Store design in worksheet in the Options subdialog box.

Every 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, this column is labeled CenterPt. If you create a Plackett-Burman or general full factorial design, this column in labeled 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, these names display 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 Data window or with Modify Design.

If you did not assign factor levels in the Factors subdialog 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. 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.

Caution

When you create a design using Create Factorial Design, Minitab stores the appropriate design information in the worksheet. 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 worksheet data. If you do not, you may corrupt your design. See Modifying and Using Worksheet Data.

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.