Page 304 - Design for Six Sigma a Roadmap for Product Development

274 Chapter Eight

Information axioms are axioms entertained in axiomatic design. They
are self-evident and have been learned from a large pool of observa-
tions. While the postulate is a synthetic proposition, the contradictory
of which though difficult to imagine, nevertheless remains conceivable,
the axiom would be an analytic proposition, the denial of which is not
accepted. As such, a science must start from indemonstrable princi-
ples; otherwise, the steps of demonstration would be endless.
The two design axioms suggested by (Suh 1990) are prominent
examples of empirical design principles proven to be beneficial as evi-
denced by application growth and industrial coverage. The employ-
ment of axioms in design seems to be promising because history tells
us that knowledge based on axioms will continue to evolve through
theorems and corollaries as long as the axioms are maintained.

A.1 Axiomatic design corollaries*

Corollary 1: (Decoupling of Coupled Designs)
Decouple or separate parts or aspects of a solution if FRs
are coupled or become interdependent in the designs
proposed.
Corollary 2: (Minimization of FRs)
Minimize the number of FRs and constraints.
Corollary 3: (Integration of Physical Parts)
Integrate design features in a single physical part if FRs
can be independently satisfied in the proposed solution.
Corollary 4: (Use of Standardization)
Use standardized or interchangeable parts if the use of
the parts is consistent with FRs and constraints.
Corollary 5: (Use of Symmetry)
Use symmetrical shapes and/or components if they are
consistent with the FRs and constraints.
Corollary 6: (Largest Design Tolerance)
Specify the largest allowable tolerance in stating FRs.
Corollary 7: (Uncoupled Design with Less Information)
Seek an uncoupled design that requires less information
than coupled designs in satisfying a set of FRs.

*A corollary is an immediate consequence of a result already proved. Corollaries usu-
ally state more complicated theorem in a language simpler to use and apply.