Page 117 - Design for Six Sigma a Roadmap for Product Development

92 Chapter Three

We will use the notation ICOV for short to indicate the four DFSS
phases, presented below.
DFSS as defined in this book has two tracks: deployment and appli-
cation. By deployment, we mean the strategy adopted by the adopting
deploying entity to select, scope, and prioritize projects for application.
The aspects of DFSS deployment are presented in Chap. 4. In what fol-
lows, we assume that the deployment strategy is in place as a prereq-
uisite for application and project execution.

3.7.1 Phase 1: Identify requirements (I)
DFSS projects can be categorized as design or redesign of an entity.
“Creative design” is the term that we will be using to indicate new
design, design from scratch, and incremental design for redesign or
design from a datum design. In the latter case, some data can be
used to refine design requirements. The degree of deviation of the
redesign from datum is the key factor on deciding on the usefulness
of relative data.

Step 1: Draft project charter. This is almost the same as that of the
DMAIC improvement project. However, project duration is usually
longer and initial cost is usually higher. Longer project duration is due
to the fact that the company is designing or redesigning a different
entity, not merely patching up the holes of an existing one. Higher ini-
tial cost is due to the fact that there are many more customer require-
ments to be identified and studied, since one needs to identify all
important critical-to-satisfaction (CTS) metrics to conceive and opti-
mize better designs. For the DMAIC case, one may only work on
improving a very limited subset of the CTSs.

Step 2: Identify customer and business requirements. In this step, cus-
tomers are fully identified and their needs collected and analyzed,
with the help of quality function deployment (QFD) and Kano analy-
sis. Then the most appropriate set of CTSs metrics are determined in
order to measure and evaluate the design. Again, with the help of
QFD and Kano analysis, the numerical limits and targets for each
CTS are established.
In summary, following is the list of tasks in this step. Detailed expla-
nations will be provided in later chapters.

■ Identify methods of obtaining customer needs and wants.
■ Obtain customer needs and wants and transform them into the
voice-of-customer (VOC) list.
■ Translate the VOC list into functional and measurable requirements.