Although Taguchi's approach towards robust parameter design introduced
innovative techniques to improve quality, a few concerns regarding his
philosophy have been raised. Some of these concerns relate to the signal
to noise ratios defined to reduce variations in the response, and some
others are related to the absence of the means to test for higher-order
control factor interactions when his orthogonal arrays are used as inner
arrays for the design. For these reasons, other approaches to carry out
robust parameter design have been suggested including response modeling
and the use of 
in the place of the signal to noise
ratios in the dispersion model. In response modeling, the noise factors
are included in the model as additional factors, along with the other
control factors. Details of these methods can be found in theory books
published on the subject.
See Also:
Taguchi's Robust Parameter Design Method
