Contents
- Index
Robustness
Taguchi has emphasized the importance of robust designs. A robust product or process is one that is less sensitive to variation of the inputs. That way the inputs can continue to vary but less of this variation is transmitted to the output. This minimizes the need to tighten tolerances.
Robustness is achieved by careful selection of targets for the inputs. Visualize a plot of the effect of an input on the output. By selecting a target for the input where the slope is less, the amount of variation transmitted from the input to the output is reduced.
In VarTran, robust designs are achieved by finding the set of targets minimizing the defect rate or maximizing Cpk. This minimizes the transmitted variation while driving the average to its ideal value. Robustness can also be achieved when worst-case tolerances are used by maximizing the distance inside specification.