Page 371 - Design for Six Sigma a Roadmap for Product Development

Theory of Inventive Problem Solving (TRIZ) 341

Axiomatic design TRIZ

Corollary 4: Use of standardization. Use No patterns, principles, or tools
standardization or interchangeable parts correspond to this corollary. TRIZ focuses
if the use of these parts is consistent with its studies on inventive problem solving,
FRs and constraints. This corollary states so it pays less attention to the
a well-known design rule: Use standard standardization and interchangeability of
parts, methods, operations and routine, physical components.
manufacture, and assembly. Special parts
should be minimized to decrease cost.
Interchangeable parts allow for the
reduction of inventory, as well as the
simplification of manufacturing and
service operations; that is, they reduce
the information content.
Corollary 5: Use of symmetry. Use Principle 4: Asymmetry (one of 40
symmetric shapes and/or arrangements if inventive principles) in TRIZ is in
they are consistent with the FRs and opposition to corollary 5 in AD. TRIZ and
constraints. It is self-evident that AD propose opposite principles because
symmetric parts are easier to AD theory states the general rules of
manufacture and easier to orient in engineering design, but TRIZ
assembly. Not only should the shape be methodology concentrates its studies on
symmetric wherever possible, but hole the inventive problem-solving techniques.
location and other features should be These techniques are derived from the
placed symmetrically to minimize the patent database, which relates to novel
information required during manufacture methods and unique ideas.
and use. Symmetric parts promote
symmetry in the manufacturing process.
Corollary 6: Greatest tolerance. Specify No corresponding tools are found in
the maximum allowable tolerance in TRIZ. Corollary 6 is a general rule of
stating functional requirements. design and has nothing to do with
invention.
Corollary 7: Uncoupled design with less The 40 inventive principles. These
information. Seek an uncoupled design principles provide the techniques to
that requires less information than overcome contradictions.
coupled designs in satisfying a set of FRs.
This corollary states that if a designer
proposes an uncoupled design which has
more information content than a coupled
design, then the designer should return to
the “drawing board” to develop another
uncoupled or decoupled design having
less information content than the coupled
design.
Theorem 1: Coupling due to insufficient Substance-field analysis states that any
number of DPs. When the number of properly functioning system can be
DPs is less than the number of FRs, modeled with a complete substance-field
either a coupled design results or the FRs triangle and any deviation from a
cannot be satisfied. “complete” triangle, for example, missing
one element, reflects the existence of a
problem.