Page 41 - Six Sigma for electronics design and manufacturing

Six Sigma for Electronics Design and Manufacturing
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Table 1.1 Criteria rating (CR) to select a solder system for PCB assembly
Weight
A
D
C
B
Criterion
70/7
Resistance
50/5
70/7
10
60/6
Quality
10/1
80/8
80/8
10/1
10
3
30/10
Foaming
21/7
21/7
30/10
TLV
32/8
24/6
40/10
32/8
4
40/10
40/10
4
History
24/6
40/10
30/10
3
30/10
30/10
12/4
Supplier
254
237
Total
220
195
3
4
2
1
Rank
with its own weight or rank of importance. The selection team decides
on the criteria topics and their relative weight based on team discus-
sions and members’ individual experiences. Each alternative solder-
ing material is then rated against each criterion, and a relative score
is given. In this example, both the criteria weight and the alternative
score were recorded with a maximum value of 10. This choice is arbi-
trary and smaller numbers can be used for the maximum, such as 3,
5, or 9. Each alternative score is multiplied by the criteria weight and
recorded in the table. The total weighted score for each alternative is
then calculated, and the final decision is selected based on the highest
score. In the case shown in Table 1.1, alternative D has the highest
score and should be selected.
1.8.3 Marketing
Tools such as customer surveys and competitive analyses are em-
ployed. These are traditional elements used by marketing to deter-
mine customer needs and perceptions about the company’s products
versus their competition.
In its simplest form, QFD could be used as a relationship matrix
whose input is the customer requirements or needs, and outputs are
the product specifications. The QFD process is an interaction between
the customer needs and the product characteristics, tempered by a
competitive analysis and a ranking of the importance of the different
customer needs. The QFD matrix is commonly known as the “house of
quality,” or QFD chart. A simplified approach to the general QFD
chart is shown in Figure 1.2. The “hat” on top of the matrix is used to
indicate the presence, if any, of interaction(s) between the various
product design characteristics. This interaction should be considered
when setting the final product specifications. For example, in a disc
design, changing the disc characteristic or storage capacity might in-
fluence other characteristics such as the data access time for the disc.