Blocking on fractional factorial designs is relatively easy in Minitab as long as we let Minitab supply the effects to confound with block. As usual for a fractional factorial design, enter the total number of factors you want to analyze in the Number of Factors box in the Create Factorial Design menu. Select Designs and choose the appropriate fraction (full factorial, 1/2 fraction, etc.) you would like to set up. Select the appropriate number of blocks, return to the main dialog box and, as usual, unselect the Randomized Runs box. Return to the main menu, click OK and your fractional factorial design will be selected for you. Minitab will print the alias structure of the preselected design in its Session window. Note that the design generators for the fractional factorial are listed first and then the block generators are listed. In the worksheet, the runs are grouped by block.
If you have to specify a custom block (as in the exercise we discussed in class), you select 2-level Factorial (Specify Generators) in the main Design dialog box. After selecting the design, select Generators and then enter the block generators in the Block dialog box. In our example, the default half-fraction with two blocks had design generator D=ABC and block generator AB but we needed D=BC as our design genrator and AC as our block generator. In that case, we simply enter D=BC in the design generator box and and AC in the block dialog box.
After running your experiment, analysis proceeds in the usual fashion. Note that Minitab doesn't treat the block like an effect so that, for instance, the effects plot has d-1 fewer effects than usual (where d is the number of blocks).