Page 162 - Design for Six Sigma a Roadmap for Product Development

136 Chapter Five

such as TRIZ* (e.g., ideal final result) and axiomatic design† (e.g.,
axiom 1), which are good sources for evaluating consumer appeal and
areas of likes or dislikes.

5.3.3 Understand the voice of the customer
(DFSS algorithm step 2)
The identification of key customer design wants describes how the “voice
of the customer” is collected and analyzed. A major step is listening to
customers’ capture wants and needs through focus groups, interviews,
councils, field trials and observations, surveys, and so on. In addition, the
team needs to analyze customer complaints and assign satisfaction per-
formance ratings to design product and service attributes using a
method called quality function deployment (QFD) (see Chap. 7). Market
research is gathered in two ways: (1) through indirect information,
obtained from surveys, questionnaires, competitive benchmarking and
projections, consumer labs, trade journals, the media, and so on and
(2) through direct customer engagement, including current, potential,
and competitors’ customers—from interviews, focus groups, customer
councils, field observations and trials, and any other means appropriate.

Identify customer satisfaction attributes (DFSS algorithm step 2).
Attributes are potential benefits that the customer could receive from
the design and are characterized by qualitative and quantitative data.
Each attribute is ranked according to its relative importance to the
customer. This ranking is based on the customer’s satisfaction with
similar design entities featuring that attribute (incremental design
case). A model recommended for data characterization was developed
by Robert Klein [cited by Cohen (1995)]. Klein describes two ways to
measure importance of customer wants and needs: direct method or by
inference from other data. Attribute importance measured by the
direct method is called “stated” importance. The method for inferring
importance is conducted by measuring how strongly satisfaction with
a specific attribute rates to overall design satisfaction. Attribute
importance measured by this indirect method is called “revealed”
importance. The Klein model uses both types of importance of each
attribute to classify customer wants and needs into four quadrants
(Fig. 5.5). This analysis identifies the key customer satisfaction attrib-
utes for further research studies.

*TRIZ is the Russian acronym for theory of inventive problem solving (TIPS), a sys-
tematic innovation technique developed by Genrich Altshuller of the former Soviet Union.
†A perspective design method developed by Professor N. P. Suh of MIT (Cambridge,
Mass.). See Chap. 8.