Page 49 - Six Sigma for electronics design and manufacturing

The Nature of Six Sigma and Its Connectivity to Other Quality Tools
19
Table 1.2 HP 34401A multimeter DFM results
Previous
generation
DFM metric
%
100
80
200
Material $
250
100
Nonmaterial $
55
210
100
37
Assembly time
33
100
Average repair time
400
Number of mechanical parts
100
190
30
172
100
Number of fasteners
31
Number of fastener types
8
8
100
100
Number of connects/disconnects/adjusts HP 34401A generation Previous similar
120
36
Final assembly part count 40 100 153
Total parts 68 100 190
Total part numbers 77 100 150
Number of suppliers 70 100 N/A
Inventory days 4 100 100
Throughput 100 100 100
First year engineering change orders 0 100 58
(ECOs)
ples during the design stage. In addition, the new product was in-
troduced to manufacturing without any engineering change orders
(ECOs) in the first year of production. A typical successful new de-
velopment project for a new product using DFM could include the
following activities:
Score product and part designs in breadboard or early prototype
stage, prior to initiating CAD drawings. This is important, since
once the drawings are completed, it is difficult for design engineers
who invested valuable time in the current drawings to redraw
them based on DFM evaluations.
Identify difficult assembly steps and determine if part design
changes can make them easier to assemble.
Test for redundant parts and review the use of nonstandard parts.
Based on the DFM review, simplify and redesign the parts or final
product, using competitive benchmarks, especially if the competi-
tion is successfully applying DFM. This design review may include
changing process plans or assumptions. Generate a new design
that is more efficient by eliminating redundant parts, making parts
symmetrical and minimizing assembly motions.
Rescore the new design and weigh benefits of redesign versus cost
and quality adverse consequences, if any. Consider the impact on
schedule, tooling, production, and part cost.
Pursue chosen design approach.