Page 203 - Six Sigma for electronics design and manufacturing

Six Sigma for Electronics Design and Manufacturing
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2. The quality and cost relationship. The relationship of quality and
cost are explored in Section 6.2 through the quality loss function
(QLF). Formulations and examples of this system are given, and
its use in estimating the relative value of making products to tar-
get or reducing variability explored. In addition, the use of this
function to set factory process targets is shown to be a trade-off of
defect removal either in the manufacturing plant or at the cus-
tomer site.
3. Electronic products cost estimating systems for PCB fabrication. In
Section 6.3, the technologies used for PCB fabrication and assem-
bly are reviewed and their costs are quantified based on their man-
ufacturing operations and complexity factors. A cost model for PCB
fabrication is presented with a case study. The cost and quality as-
sessment has to be tempered by other factors such as design time
and new product introduction impact.
4. Electronic products cost estimating systems for PCB assembly. In
Section 6.4, several systems are examined for determining the cost
of PCB assembly. These systems vary in their complexity, from
simple PCB components’ material-cost-based systems to the more
complex quality-based cost models, including a cost and quality
model to examine the tradeoffs in design and manufacturing. De-
fects generated by alternative design, manufacturing and test
strategies can be examined and a decision made for the lowest-cost
alternative. Each system is discussed with examples and case
studies.
6.1 The Overall Electronic Product Life Cycle
Cost Model
The manufacturing costs of products are highly dependent on life cy-
cle stage, as shown in see Figure 6.1. The first stage is called start-up
or market development. During this stage, emphasis is on the per-
formance of the product. Features such as speed, capacity, response
time, and other “bells and whistles” dominate the product cycles. At
this stage, the benefits of the product to the customer are perceived to
be very high in increased productivity or personal comfort and satis-
faction. The number of competitors is large, since entry into the mar-
ket is wide open, and a new company can establish a niche in the mar-
ketplace for a relatively low investment. Product development during
the start-up stage is marked by the intense drive to arrive at the mar-
ket as early as possible, with minimum concern over manufacturing
cost. A good indicator of this stage is the number of wire cuts and
changes to printed circuit boards (PCBs) in new products. The quality