DOE Fractional Factorial Design
This guide provides instructions on designing a fractional factorial experiment using the Screening Design platform. Fractional factorial experiments are used when it's more efficient to not perform an experimental run for every possible treatment combination as is done in a full factorial design.
Create the Design (Screening Design)
- Open the platform under DOE > Classical > Two Level Screening > Screening Design.
- Specify the Response(s):
- Double-click on Y, under Response Name, to name the response.
- If needed, change the response Goal and Upper and Lower Limits. Click Add Response to add additional responses.
- Specify the Factors:
- Add the desired number of Continuous (2-level) and/or 2- or 3-Level Categorical factors.
- Add the factor names and levels.
- Click Continue. From the Design List, select the desired design and click Continue. Note: Choose an appropriate block size (i.e., runs within each block) if there is a blocking variable that needs to be accounted for in the experiment. Full factorial designs are also available to choose.
- Specify the Run Order (default is Randomize), the Number of Center Points and the Number of Replicates (the number of additional sets of runs for each design point). Here we created an unreplicated fully randomized 25-2 fractional factorial design with 3 center points, totaling 11 runs.
- Select Make Table to generate the design table (or Back to make changes). The Screening and Model scripts will be saved to the data table and the design specification window stays open to change or regenerate the design.
Notes:
- Select Evaluate Design to view properties of the design.
- The Easy DOE platform (under DOE menu) provides a guided workflow to step through the process of creating and analyzing experiments and is an alternative to the steps above for creating a design.
- Screening designs can also be generated from the Custom Design platform.
Visit Design of Experiments Guide in JMP Help to learn more.