Page 47 - Six Sigma for electronics design and manufacturing

The Nature of Six Sigma and Its Connectivity to Other Quality Tools
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The competitive analysis portion of the QFD chart is used mostly
for product design. It outlines the team’s evaluation of the position of
the company’s current products against the competition as perceived
by the customers. The team could decide to counteract a particular de-
ficiency of the current design in meeting one of the customer needs,
and therefore add a multiplier to the importance factor. This multipli-
er forces the design team to focus on reversing this deficiency in the
new product. This occurs when the deficient customer need generates
a higher score when multiplied by the importance factor.
As was shown by both design and manufacturing examples, QFD
can be an excellent tool to improve the design quality and to attain six
sigma levels through focusing on customer needs. In the design exam-
ple, it can be used to show which specifications should be widened and
which can be left alone or even reduced. Widened specifications would
affect the numerator of the six sigma equation, making the goal of six
sigma easier to achieve. In the manufacturing example, it was used as
a defect reduction tool by the manufacturing quality team to identify
which process should be investigated to reduce defects and hence
manufacturing variability. Such processes could undergo a design of
experiments (DoE) project to reduce variability, which is the denomi-
nator of the six sigma equation.
It is important to note that QFD is a process designed to solicit cus-
tomer needs from experienced users of established products or
processes. In both examples, those directly involved in the use of the
product, such as cable installers or the recipients of PCBs, were part
of the customer needs assessment. Products and processes using new
technology would benefit less from QFD. For example, it would not be
beneficial for slide rule users to quantify their experience into cus-
tomer needs for calculators. In this case, more traditional marketing
research methods could substitute for QFD.
1.9 Design for Manufacture (DFM)
The principles of design for manufacture and design for electronic as-
sembly have been widely been used in industry through design guide-
lines and DFM systems for effectively measuring the efficiency of de-
signs for manufacture and cost. The most important guidelines for
DFM design for parts are:

1. Use minimum parts types
2. Use standard components
3. Use parts that fit or snap together with no fasteners
4. Tools are not required for product assembly