Performance-Measures Independent of Adjustment - Discussion

Leon, Shoemaker, and Kackar's (LSK) explanation and extension of Taguchi's Signal-to-Noise ratio (SN) is interesting. I am in agreement with them in the use of Taguchi's SN ratio in parameter design results in the minimization of the expected loss only if certain assumptions about the loss function and the underlying model of the product or process hold. Here, I will discuss the following issues concerning the concept of a Performance Measure Independent of Adjustment (PERMIA) which was introduced by LSK as an extension of SN ratios.