Page 128 - Design for Six Sigma a Roadmap for Product Development

Product Development Process and Design for Six Sigma 103

In addition, the task of implementing changes to obtain the Six Sigma
capability is easier, to a large degree, in an uncoupled as opposed to a
coupled design.
The DFSS deployment is best suited when it is synchronized with
the design life cycle. The next section highlights a generic design
process that will provide some foundation. The authors realize that
many variants to what is proposed do exist; some more than others,
stress certain aspects that best suit their industry. This variance is
more prominent in long-term, low-volume industries versus short-
term development cycles with high production volume.

Appendix: Historical Development in Design
The research in the design arena started in Europe. Above all, the
Germans developed over the years some design guidelines that continued
to improve at a consistent pace. A huge body of research has been pub-
lished in German on the design practice. Unfortunately, only a limited
portion has been translated into English. Most of these efforts are listed
in Hubka (1980) and Phal and Beitz (1988). The Germans’ design schools
share common observations. For example, a good design entity can be
judged by its adherence to some design principles; the design practice
should be decomposed to consecutive phases, the need for methods for
concept selection, and so on. Besides the Germans, the Russians devel-
oped an empirical inventive theory with promises to solve difficult and
seemingly impossible engineering problems, the so-called TRIZ or theory
of inventive problem solving (TIPS). TRIZ is an example of the basic prin-
ciples for synthesis of solution entities (Altshuler 1988, 1990), Rantanen
(1988), Arciszewsky (1988), Dovoino (1993), Tsourikov (1993), Sushkov
(1994), and Royzen (2002). TRIZ, the Russian acronym to TIPS, is based
on inventive principles devised from the study of more than 1.5 million of
the world’s most innovative patents and inventions. TRIZ was conceptu-
alized by Dr. Gerikh S. Altshuler, a brilliant Russian inventor, in 1946.
TRIZ is an empirical theory that was devised along the lines of inventive
problem solving, functional analysis, technology prediction, and contra-
diction elimination. Contradiction is synonymous with the coupling
vulnerability in axiomatic design (Suh 1990).
The concern of reducing vulnerability to foster customer satisfac-
tion in the design entities continued with the work of the English
researcher Pugh (1991, 1996). Pugh proposed a matrix evaluation
technique that subjectively weighs each concept against the impor-
tant technical criteria and customer concerns from a total perspec-
tive. Pugh (1991) discussed the role of systematic design and concept
selection for both conventional and nonconventional (creative) product
situations.