Page 165 - Design for Six Sigma a Roadmap for Product Development

Design for Six Sigma Project Algorithm 139

The objective of the planning matrix evaluation is to broaden the
team’s strategic choices for setting customer performance goals. For
example, armed with meaningful customer desires, the team could
direct their efforts at either the strengths or weaknesses of best-in-
class competitors, if any. In another choice, the team might explore
other innovative avenues to gain competitive advantages.

5.3.5 Refine and prioritize customer wants,
needs, and delights (DFSS algorithm step 2)
The objective of this step is to refine and prioritize customer wants,
needs, and delights. The array of customer attributes should include
all customer and regulatory requirements, together with social and
environmental expectations. It is necessary to understand require-
ment and prioritization similarities and differences in order to under-
stand what can be standardized (universally) and what needs to be
tailored (locally).
Customer attributes and social, environmental, and other company
wants can be refined in a matrix format for each identified market
segment. These wants are also called the WHATs in the QFD litera-
ture. The customer importance rating* is the main driver for assigning
priorities from both the customer and the corporate perspectives, as
obtained through direct or indirect engagement forms with the
customer (see Sec. 5.3.3, subsection on identifying customer satisfac-
tion attributes).

Identify CTS array as related to the list of wants and needs for prioritization
(DFSS algorithm step 2). The critical-to-satisfaction (CTS) array is an
array of design features derived by the DFSS team to answer the
WHATs array. The CTS array is also called the “HOWs” array. Each
initial WHAT needs operational definition. The objective is to determine
a set of critical-to-satisfaction requirements (CTSs) with which WHATs
can be materialized. The answering activity translates customer expec-
tations into design criteria such as speed, torque, and time to delivery.
For each WHAT, there should be one or more HOWs describing a means
of attaining customer satisfaction. For example, a “cool car” can be
achieved through body style (different and new), seat design, legroom,
lower noise, harshness, and vibration requirements. At this stage only
overall requirements that can be measured and controlled need to be
determined. These substitute for customer needs and expectations and
are traditionally known as substitute quality characteristics. In this
book, we will adopt the “critical to” terminology aligning with Six Sigma.

*Also known as customer desirability index (CDI). See Chap. 7 for more details.