What is the relationship between the quality loss function and quality characteristic fluctuations in DFSS training consulting?

Fluctuations in quality characteristics (i.e. deviations in product performance from design target values) are the cause of quality losses and quality problems. Dr. Taguchi established a quality loss function to describe the relationship between quality loss and quality fluctuations.

Mathematical expectation of a batch of products L(y): When Y obeys the normal distribution N(μ, σ2): σ2 and (μ-m)2 determine the shape and position of the curve j(y), while k determines the quality

The shape of the loss function L(y); there are two goals for robust design: one goal is to minimize [s2+(m-m)2], that is, the curve j(y) is very steep and the mean is close to m; the other goal is to minimize k

, that is, the curve L(y) is very flat, thus minimizing the quality loss of the product.