Fractional Factorial Designs for Multistep Processes

• Activity Number: 329
• Type: Invited
• Date/Time: Tuesday, August 6, 2013 : 10:30 AM to 12:20 PM
• Sponsor: Section on Physical and Engineering Sciences
• Author(s): Jose Gregorio Ramirez and Murat Kulahci and Randall David Tobias*+
• Companies: Amgen, Inc. and Technical University of Denmark and SAS Institute, Inc.
• Keywords: Fractional factorial design ; split-plot design ; multistep designs

Abstract

Kulahci, Ramirez, and Tobias (2006) showed that minimum aberration is not designed to distinguish among the different types of two-factor interactions in fractional factorial split-plot designs. We expand this idea to fractional factorial designs in situations where more than one split is involved, that is, multistep processes. We give design and model constraints for generating fractional factorial designs in multistep situations, and demonstrate the use of the FACTEX procedure of SAS/QC® Software to find designs for particular three-, four-, and five-step processes.

Reference: Kulahci, M., Ramírez, J.G., and Tobias, R. (2006) "Split-Plot Fractional Designs: Is Minimum Aberration Enough?" Journal of Quality Technology, 31, 56-64.