The Taguchi Methods and Robust Design

Products have characteristics that describe their performance relative to customer requirements or expectations (Ross (1988)). The quality of a product/process is measured in terms of these characteristics. Typically, the quality is also measured throughout its life-cycle. The ideal quality a customer can expect is that every product delivers the target performance each time the product is used under all intended operating conditions and throughout its intended life and that there will be no harmful side effects (Phadke (1989)). The quality of a product is measured in terms of the total loss to society due to functional variation and harmful side effects (Taguchi (1986)). The ideal quality loss is zero. 

A leading indicator of quality is required by which one can evaluate the effect of changing a particular design parameter on the product s performance. This indicator is called signal-to-noise ratio. It isolates the sensitivity of the system s performance to noise factors and converts a set of observations into a simple number. 

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