“…The review noted several Six Sigma case illustrations employing full and factorial experimental design for process optimization (Vinodh et al , 2014; Gijo et al , 2014; Zhang et al , 2015; Gijo and Scaria, 2010; Chen and Lyu, 2009; Lee et al , 2009; Johnson et al , 2006a, b, 2012; Leitnaker and Cooper, 2005; Gijo and Rao, 2005). Many of these industrial experimentation studies used Taguchi OA and signal to noise (S/N) ratio for reducing variation in the processes (Vinodh et al , 2014; Saravanan et al , 2012; Gijo and Scaria, 2010; Singh et al , 2007; Gijo, 2005).…”