PARAMETER DESIGN FOR SIGNAL-RESPONSE SYSTEMS - A DIFFERENT LOOK AT TAGUCHIS DYNAMIC PARAMETER DESIGN

A recent trend in the industrial applications of robust parameter desi gn is to consider complex systems which are called ''systems with dyna mic characteristics'' in Taguchi's terminology or signal-response syst ems in this paper. This potentially important tool in quality engineer ing lacks a solid basis on which to build a rigorous body of theory an d methodology The purpose of this paper is to provide such a basis. We classify signal-response systems into two broad types: measurement sy stems and multiple target systems. Three issues are then of fundamenta l importance. First, a proper performance measure needs to be chosen f or system optimization, and this choice depends on the type of system. Taguchi's dynamic signal-to-noise ratio is shown to be appropriate fo r certain measurement systems but not for multiple target systems. Sec ond, there are two strategies for modeling and analyzing data: perform ance measure modeling and response function modeling. Finally, the pro per design of such experiments should take into account the modeling a nd analysis strategy. The proposed methodology is illustrated with a r eal experiment on injection molding.