Page 39 - Six Sigma for electronics design and manufacturing

Six Sigma for Electronics Design and Manufacturing
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Design engineers normally set the product specifications, whereas
manufacturing engineers are responsible for production variability.
The object of increasing the process capability to six sigma or Cp = 2 is
twofold: increase the product specifications, either by widening them
or reducing the manufacturing variability. Either effort can have a
positive effect on reaching six sigma.
The design specifications for any part or process are related to the
top published product specifications. Ultimately, it is the customer
that determines the relative importance of each specification and the
desired level of performance. Good market research and project man-
agement for new products can determine the best level of specifica-
tion. This level can be set to balance the wishes of the customer, tem-
pered by what the competition is offering and considering inputs from
design and manufacturing engineers as to the difficulty of meeting
that specification level.
The quality of supplied parts and the efforts of the manufacturing
engineers in production solely determine the denominator of the six
sigma equation, or the manufacturing variability. Implementing the
traditional quality tools of manufacturing, such as statistical quality
control (SQC) and associated quality tools, can reduce the manufac-
turing variability. The tools of SQC and their relationship to process
capability are discussed in Chapter 3.
The Cp formula can then be rewritten as
specifications design engineering customer
Cp = = = (1.4)
variability manufacturing engineering supplier
1.6 Definitions of Major Quality Tools and How
They Affect Six Sigma
Before a six sigma effort is launched, it is mandatory to have a well-
defined and successfully managed total quality management (TQM)
program. The tools of TQM encourage the use of well-established
methodologies for quantifying, analyzing, and resolving quality prob-
lems. A brief description of the TQM tools and examples of each will
be given in Chapter 2.
1.7 Mandatory Quality Tools
It is widely recognized that TQM tools and techniques should be in
full utilization before the launch of any six sigma program. SQC
should also be well implemented in the organization, with wide use of
control charts in manufacturing and the supply chain. Both of these
tools will be discussed in Chapter 3 regarding process control.