Alpha mistake of Taguchi method with L18 array for STB (smaller-the-better) type QCH (quality characteristic) using simulation

The alpha mistake of Taguchi method is investigated for the smaller-the-better type quality characteristic with L18 (2¹ × 3⁷) array using simulation. The results showed that the Taguchi method might result in identifying incorrectly some insignificant factors as significant. In conclusion, Taguchi's quality engineering concepts are valuable, but his statistical tools, including: signal-to-noise ratio, testing at F value of four and pooling-up techniques, are found inefficient tools for robust design.