Efficient line changeover: the key to lean manufacturing
hidden costs for electronics manufacturers. added revenue associated with improved 2. Improve operating efficiency
The root cause of high cost of rework, non- line changeover, the operation of a major by improving equipment
revenue-generating operations, lost revenue Tier 1 electronics manufacturing service utilization as a direct result
due to down time, work-in-process manage- (EMS) provider was studied. The area of of eliminating non-scheduled
ment and poor quality can all be traced in study focused on the actual labor costs equipment idle time.
some part to poor equipment utilization.
1
and equipment utilization on their screen 3. Maintain process reliability in
In most of the industrial countries, it printers and pick and place machines. terms of solder paste deposi-
has become increasingly costly, or totally tion and placement accuracy.
unacceptable, to perform post-assembly Operational details
rework. Additional overhead and labor Assembly lines: 10 Setup and changeover efficiency
costs related to equipment underutilization Effected equipment per line: The setup and changeover times were
can jeopardize a business that is margin- One (1) automated screen printer, and two measured and recorded for each of the
ally profitable in the first place. Building (2) placement machines affected production line equipment. Mul-
the product right the first time is essential. Existing average board support setup time: tiple measurements were taken to account
There is a contradictory message operators 15 minutes, 22 seconds per machine for in-operator and shift-to-shift variations.
are getting. They are being told to change- Average number of changeovers per line Manual setup of standard support tooling
over lines quickly without sacrificing qual- per day: 2 for the screen printers and placement ma-
ity. As the changeover of lines has become Total number of changeovers per year: chines required an average of 15 minutes
more frequent, the opportunity for human 5,000 and 22 seconds per machine, as shown in
error increases dramatically. If an operator Table 1.
has to struggle with antiquated tooling and Goals and objectives An immediate reduction in the setup
processes, equipment downtime, or non- The objectives of the study were to reduce and changeover time required for board
revenue-generating line stoppages increase. the changeover and setup time of the support was observed within two weeks
The solution is to implement systems screen printers and placement machines after installing substrate support systems in
and procedures that enable production from the present manual setup operation, the screen printer and placement machines
operators to changeover lines with minimal and: as shown in Table 2. Setup and changeover
difficulty without endangering quality. 1. Reduce changeover/setup time continued to improve as operators
time of board support tooling became accustom to the substrate support
case study by 50% to 7.5 minutes per system after two months of operation as
In order to determine the cost savings and machine. shown in Table 3.
measurement op #1 op #2 op #3 measurement op #1 op #2 op #3 measurement op #1 op #2 op #3
1 720 1,001 930 1 241 360 370 1 90 134 138
2 780 930 980 2 250 350 395 2 93 130 147
3 908 920 972 3 250 345 384 3 93 128 143
4 924 936 1.012 4 280 353 360 4 104 131 134
5 851 894 871 5 401 310 354 5 149 115 132
6 872 926 862 6 310 330 405 6 115 123 151
7 950 984 912 7 330 360 360 7 123 134 134
8 870 1,024 1,012 8 260 400 402 8 97 149 150
9 720 1,036 1,036 9 280 390 412 9 104 145 153
10 840 920 925 10 201 384 376 10 75 143 140
11 812 876 967 11 300 372 392 11 112 138 146
12 936 924 984 12 370 305 385 12 138 113 143
13 903 1,071 960 13 320 302 408 13 119 112 152
14 923 921 940 14 310 405 356 14 115 151 132
Total Time 12,009 13,363 13,363 Total Time 4,103 4,966 5,359 Total Time 1,526 1,847 1,994
(sec) (sec) (sec)
Avg. Time 858 955 955 Avg. Time 293 355 383 Avg. Time 109 132 142
(sec) (sec) (sec)
Avg. Setup 922 seconds Avg. Setup 344 seconds Avg. Setup 128 seconds
Time or 15 mm, 22 sec Time or 5 min, 44 sec Time or 2 min, 8 sec
Table 1. Equipment setup time with standard sup- Table 2. Equipment setup time with substrate sup- Table 3. Equipment setup time with substrate sup-
port tooling. port system after two weeks of use. port system after two months of use.
36 – Global SMT & Packaging – March 2009
www.globalsmt.net
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62