Page 266 - Design for Six Sigma a Roadmap for Product Development

236 Chapter Seven

The highest CTSs with the highest importance ratings are the most
important. For example, “Know our products and processes” has the
highest rating at 133. This rating is so high because it has three strong
relationships to the WHATs. The degree of difficulty is medium (rating
equal to 3) in the technical benchmarking. In addition, any CTS that
has negative or strong relationships with this CTS in the correlation
matrix should proceed to phase 2.

7.9 Summary

QFD is a planning tool used to translate customer needs and expecta-
tions into the appropriate design actions. This tool stresses problem
prevention with emphasis on results in customer satisfaction, reduced
design cycle time, optimum allocation of resources, and fewer changes.
Together with other DFSS tools and concepts, it also makes it possible
to release the designed entity at Six Sigma level. Since the customer
defines quality, QFD develops customer and technical measures to
identify areas for improvement.
Quality function deployment (QFD) translates customer needs and
expectations into appropriate design requirements by incorporating
the “voice of the customer” into all phases of the DFSS algorithm,
through production and into the marketplace. In the context of DFSS,
the real value of QFD is its ability to direct the application of other
DFSS tools to those entities that will have the greatest impact on the
team’s ability to design their product, a service or a process that satis-
fies the needs and expectations of the customers, both internal and
external.
The following items are a review of the different parts of the house
of quality. The WHATs represent customer needs and expectations.
The HOWs are critical-to-satisfaction (requirements) (CTSs) or substi-
tute quality characteristics for customer requirements that the com-
pany can design and control. Relationships are identified between
what the customer wants and how those wants are to be realized.
Qualitative correlations are identified between the various HOWs.
Competitive assessment and importance ratings are developed as a
basis for risk assessment when making decisions relative to trade-offs
and compromises. Such trade-offs can be resolved with the employ-
ment of conceptual methods such as TRIZ and axiomatic design.
Because of user preferences, especially in the automotive industry, the
conventions, symbols, and even the shape of the house of quality have
evolved with use. For example, the “roof ” was added by Toyota, and
Ford added the use of arrows to denote target orientation.