Page 586 - Design for Six Sigma a Roadmap for Product Development

Design Optimization: Advanced Taguchi Robust Parameter Design 543

y=Oxidation
thickness

M=Time

d. Analysis. Time is a signal; the more time the process runs, the more
material transformation will occur. The robustness of ideal function is
an indication of the robustness of
(1) Different levels of transformation. With different time settings, dif-
ferent amounts of oxidation will occur.
(2) Controllability. If a straight-line relationship is repeatable, that
shows excellent controllability.
2. Design of an operational amplifier
a. Main function. To produce a gain in a voltage.
b. Main transformation. Energy transformation.
c. Ideal function

y=Output
voltage

M=Input
voltage

d. Analysis. An operational amplifier works in such a way that it draws
electrical power from the power source and then creates the output
signal that follows all “signatures” of the input signal. Therefore,
input signal is again a “control.” The robustness of an ideal function
is the indication of the robustness for
(1) Different levels of transformation. With varying input, there is a
varying output.
(2) Controllability. The output follows input in a straight line.
3. Measurement process
a. Main function. To measure.
b. Main transformation. This could be any of the three types—energy,
material, or signal—depending on what to measure and the mecha-
nism of measurement.
c. Ideal function