Page 327 - Design for Six Sigma a Roadmap for Product Development

Theory of Inventive Problem Solving (TRIZ) 297

the maturity stage, then we will know that it is time to develop the
next generation of this subsystem.

Contradiction analysis By using the method described in Sec. 9.2.4, we
can determine if there are any physical contradictions or technical con-
tradictions in our current system. TRIZ has many methods to resolve
contradictions.

9.3.2 Problem classification
and tool selection
After we are finished with the problem definition, we should be able to
classify the problem into the following categories. For each category
there are many TRIZ methods available to resolve the problem.

Physical contradiction
Methods. Physical contradiction resolution and separation principles.

Technical contradiction
Methods. Inventive principles.

Imperfect functional structures. This problem occurs when:
1. There are inadequate useful functions or lack of needed useful
functions
2. There are excessive harmful functions
Methods. Functional improvement methods and TRIZ standard
solutions

Excessive complexity. This problem occurs when the system is too com-
plex and costly, and some of its functions can be eliminated or combined.
Methods. Trimming and pruning.

System improvement. This problem occurs when the current system is
doing its job, but enhancement is needed to beat the competition.
Method. Evolution of technological systems.

Develop useful functions. This problem occurs when we can identify
what useful functions are needed to improve the system but we do not
know how to create these functions.
Methods. Physical, chemical, and geometric effects database.