Ergonomics research to improve productivity
Work-study, that people more familiar time and motion study, which has increased production capacity and research all forms of work provides a scientific method. It consists of two parts (method to study and work measurement), they are used to systematically detect an effect of the improvement work, it also includes some basic definitions: 1 hours refers to a worker in one hour pay for labor; machine running time refers to a machine in operation within one hour; in order to produce a certain amount of time used products including basic manual and machine work together with the time spent; workload is for the production of a product, a man or a machine, the time spent; basic work is in the ideal case and the case of non-stop delay, the completion of a satisfactory standard of design time required.
Break - unlike reasonable rest time by management or employees caused by the defect, due to time through increased production capacity has declined. Therefore, in theory, without interrupting work in the case of the basic work is required to produce a product of the absolute minimum. Does not make for effective work, any form of disruption is a waste of time. In fact, the disruption occur. Sometimes, if the machine suffered a power outage or failure, disruption is inevitable. Other cases may be caused by the management or staff. In this case, they add an invalid time. Therefore, in this case the actual working time is valid for all time and workload.
Method and proposed methods of work of existing records and critical testing of the system is developed and applied to reduce the cost of easier, more effective method as a means. Therefore, it is essentially the production operation is to reduce the workload.
The recorded data for the proposed method or a critical test is the basic method of procedure. It determines matters under each of the real reasons, and a set of all possible improvements to established plans. Although its purpose is to challenge, but its main goal is to see whether an activity can be completely removed. If they are found necessary, the target will have to modify that or change the order, or to combine it with other activities. Integration of activities, changes in work location or sequence of operations usually enable employees to achieve improved results.
Work and the determination of the main void detection and reduce the time, hours of operation and the subsequent establishment of standards related to the provisions of the Institute is such a method, this operation is implemented in the modified model.
Obviously, it only applies to a method has been implemented over the case. So when the time is very important, it is for the design, planning, organization and control to provide the basic necessary information.
Example
India's export-oriented Ambur's a stretch to help install the work lasts and finishing departments to implement a project for us to provide a good example. A full load of U-shaped production line processing system, the number of 124 × 3 rows of rollers, each in wheel put a pair of boots, its production target for the production of 672 pairs of special day class in the style of the boots, but the actual students in the average, only 605 pairs. In order to achieve the objectives required by the factory to identify the problems and provide solutions.
To do this, there is need to investigate the use of existing production lines and ergonomics research methods analyze the special problems of the bottleneck workstation. Implementation using the standard method of determination of the stopwatch is recommended to balance the production line and production of improved technology and make further recommendations. (Photo, Table 1)
Common Terminology
Basic time = (time × average compliance observed operating level) / standard operating level
Standard time = time + 3% of basic accidental discharge permit to allow 15% W
Performance level = speed relative to the standard observer's concept of the efficiency of the operator's assessment of the efficiency
Standard performance level = less than 1 business day in the case, assuming that a trained operator to know and adhere to a particular method, and the spontaneous case of work to achieve the production rate (expressed as the standard index register 100, the performance level below)
Assessment level described
0 no activity
50 is very slow, clumsy, and explore the nature of the action, showing no interest in the state of drowsiness and
75 stable, precise, orderly piece of work, supervision in custody a long time, though slow, but not deliberately waste time
100 qualified workers to operate the equivalent of a piece of light work, skilled performance. Achieve the necessary confidence in the quality and accuracy standards
125 relative to a normal operator in terms of fast, high degree of confidence, dexterity, motor coordination
150 very fast, high-intensity work and need a high degree of focus. Only by a few good operators do, and time will not last long
Process analysis
1, drawings, and Table 1 shows the double bottom gluing large (9 and 16), because the use of thermoplastic rubber sole, brush that is enough.
2, double uppers gluing (19 and 21) between the time only 3.2 minutes, this time for the PU adhesive to dry and not enough in terms of the proposed time difference of 10 to 15 minutes. Can eliminate the steps 16 and re-arrange tables for this purpose.
3, to help the second gluing surface (21) and attached at the end (23) only the time between
12.8 minutes. PU adhesive recommended for at least 25 minutes set aside time.
4, can be just 73.5 minutes off last. A total production cycle time should be 115.2 minutes, but the actual discovery, the average time of 150 minutes. Balance due to the production line per cycle due to poor transmission pause time consuming 34.8 to 45 minutes.
5, the current on the insole board to help drive is not fully raised, the machine will idle, so the operator to stop the transfer.
6, the waist to help and to help drive the furnace after the interval to the pipe into the mouth of the problem so that the glue dried out, it became necessary to repeat the process.
7, because the output of two machines to help influence the overall workflow, all other operations are restricted.
8, due to stretch to help the daily loading lasts sector plan is not complete, resulting in a lack of parts caused by the production line stopped periodically (could not help the production planning department to implement).
9, 10 breaks the morning (when the length is 15 to 20 minutes) after the time work is not in place leading to increased production lasts and cycle time.
10, due to lack of plans to help correct the lack of surface lead to unnecessary adjustment of the machine and table. Then style ingredients has led to a defective part back there to help and substandard products.
Methods
Because some of the inappropriate methods of work, some of the workstations has created a bottleneck. These bottlenecks are observed and analyzed to see whether these operations differ separation.
1, steps 9 (bonding soles), the table position requires the operator to pick up a few soles, and then back into the production line. It was observed that the average time 0.87 minutes / double. Adjust the table position can be reduced to 0.58 minutes / double.
2, steps 14, the operator on an upper ironing increased workload because of the use of the temperature is too low. After adjustment, not only to improve the technology, but also reduce the time.
3, steps 23 (installation soles) in the machine settings are not correct, the operator of the technology is not skilled. Adjusted and improved to reduce the use of time.
4, if properly painted shoes, milk, brushing in 34 steps to improve.
5, if the uppers and soles of the bonding operation is more accurate, the cleaning step 39 will be reduced.
Improved production line
1, Table 2, steps 3 (waist to help and after to help) when displayed with a standard 0.5426 minutes / double. We know that the target output is 672 pairs / frequency, so every time 0.7143 minutes with a two-up, the operator can achieve our goals.
2, steps 14 (smoothing), using the standard time is 1.46 minutes / double. This link with two employees, but did not achieve their goals, so need to add a staff.
3, steps 16 (bonding soles), the standard is 0.37 minutes / double, 9 steps have been this, so this was a halogenated had TPR soles, so no secondary operations. If necessary, they can be transferred to other operating areas.
4, steps 21 (get rid of excess adhesive), one operator can not reach 0.77 minutes / double standard, so this part of a need to increase staffing.
5, 37 steps (with cotton scrub), the standard is 0.98 minutes / double, but only one operator. To achieve the goal of the need for two operators.
Result
To reduce ineffective time, so that production capacity can be improved, this project uses ergonomics research methods. As mentioned earlier, this particular style of boots goal is 672 pairs / shift, but only to 605 pairs. The chart shows that if a reasonable plan to implement and adopt recommendations in Table 2 with a balanced production line, can reach the target yield.
Tolerate and maintain, without reducing the sense of social responsibility in the case, do everything possible to balance the production line is recommended. Because the proposed use of each part of the same production line operator based on the number of design, operating procedures and other aspects of 4,16,19,26,34 and 44 production was relatively high. These aspects of the skills of employees only vaguely or completely unskilled, they can be transferred to other operations as part of or the absence of cover.
The current production line efficiency of 54.44%, to reach 672 pairs / frequency of the target, the need will increase to 60.15% efficiency. If the efficiency to 85%, without increasing the manpower situation, production could reach 786.5 pairs / frequency (Table 3). In order to achieve the target yield, and sometimes need to work overtime, but must pay additional wages. Allows the use of recommended production line to minimize overtime costs. Implementation of the daily production planning production planning can be improved.
Table 3 also shows that by reducing the workload, only 60.15% of the labor efficiency can achieve our goals. If we consider the plant efficiency of 85%, it is recommended to use production line can produce more output than the target, it will also promote methods of work, improve working conditions and reduce worker fatigue, while improving product quality (Table 4).
Conclusion
Real need for footwear production machine and a reasonable allocation of manpower, working methods and needs proper workstation order, and have a production line balancing to maximize outputs and minimize inputs. Can reduce the use of ergonomics research work steps so that production capacity can be improved.
Photos, line stretch to help install lasts
Table 1, the original process of production line
Number operator workstation DS TS ST MP CA CB
1 upper and size test bench --- --- 0.35 2 1371.43 1165.72
2 Replace the upper, the shoe last and shoe --- --- 0.29 1 1655.17 1406.89
3 mounted in the bottom table 1 1116.28 948.84 0.43 1.5 0.024
Table 4 upper toe softened 1 1846.15 1569.23 0.26 0.016 1.0
5 toe (upper) three pairs of wet steam / 3-5 min 1.0 0.016 0.59 1 813.56 961.53
6 ago to help 1m / c 1.0 0.016 0.5045 1 951.44 808.72
7 detection, thump toe table 1.5 0.024 1020 0.40 1 1200.00
And adjust the heel height
8 back to help and after to help 1m / c 3.5 0.056 0.5426 1 884.63 751.94
9 hand-gluing soles Table 1.5 0.024 0.54 1 888.89 755.56
10 blowing hot air 1m / c 1.0 0.016 0.42 1 1142.86 971.43
11 Sulfur amorphous 140 ℃ 5 分钟 1.0 0.016 0.47 1 1021.28 868.09
12 hammer flat type 1m / c 4.0 0.064 0.48 1 1000 850
13 with the heel of 1m / c 1.5 0.024 0.52 1 923.08 784.62
14 Screed 2m / c 1.5 0.024 1.46 2 657.53 558.90
Wax by hand to the upper table 15 1.0 0.016 0.42 1 1142.86 971.43
16 hand-gluing soles (2) Table 1.5 0.024 0.37 2 1297.30 1102.71
17 Brush upper 1m / c 1.5 0.024 0.30 1 1600 1360
18 erosion (without wire brush) 1x2station m / c 2.0 0.032 0.84 2 1142.86 971.43
19 manual binding uppers (1) Table 1.5 0.024 0.538 1 892.19 758.36
Fill the bottom of the table 20 1.0 0.016 0.28 1 1714.29 1457.15
21 hand-gluing the upper (2) Table 1.0 0.016 0.59 1 813.56 691.53
22 get rid of excess glue table 1 623.38 529.87 0.77 1.0 0.016
Activated to help at the end of 65 ± 5 ℃ (surface),
23 at the end of 45 ± 5 ℃ (bottom) 5-6 seconds; 7.0 0.112 0.9067 2 1058.78 899.97
2 stations at 3bar pressure under 5 seconds
Again in 15 seconds under the pressure 43bar
5 ℃, 24 frozen integer 4 minutes 1.0 0.016 0.47 1 1021.28 868.97
25 hand-cut line of Table 4.0 0.064 0.40 112,001,020
26 will detect and use crepe soles Table 1.0 0.016 1 842.11 715.79 0.57
Edge of the adhesive removal
Clear traces of the suture 27 Table 1.0 0.016 0.31 1 1548.39 1316.13
28 to complete the upper wax table 1 1021.28 868.09 0.47
29 off lasts 1m / c 1.5 0.024 0.38 1 1263 1073.55
30 pairs test, remove the shoe table 1 1142.86 971.43 0.42 1.0 0.016
Substrate and adhesive tape
31 hand-substrate adhesion shoe table 800 1.0 0.016 0.51 1 941.18
Within the substrate table 32 dress shoes 1 905.67 769.82 0.53
33 Screed 3m / c 80 ℃ 1.5 0.024 1.27 3 1133.86 963.78
34 cotton brush 1m / c 1.5 0.024 0.61 1 786.89 668.86
Line of table 35 to detect and bake 2 2086.96 1773.92 0.46 0.024 1.5
36 hand-painted shoes, milk (1) Table 1.5 0.024 0.53 1 905.67 769.82
37 hand-painted shoes, milk (2) Table 3.0 0.048 0.52 1 923.08 784.62
38 cotton brush 1m / c 3.0 0.048 0.98 1 489.80 416.33
39 crepe rubber pieces with clean soles Table 1.0 0.016 1 761.90 647.62 0.63
Shoe bench support 40 placed 1.5 0.024 1.09 2 880.73 748.62
41 Table 1.09 2 880.73 748.62 tie
42 wax polishing 1m / c 2.0 0.032 0.54 1 888.89 755.56
43 detects table 1 1263.16 1073.69 0.38 0.016 1.0
44 mark (with a table) 1.0 0.016 0.34 1 1411.76 1073.69
45 bags (with a table) 1.0 0.016 0.49 3 2938.78 2497.96
Shoe size 46 test and see Table 4.5 0.072
Total 72 1.152 58
Notes:
The distance between the DS workstation (m)
ST standard time (minutes / double)
CA 100% efficiency of the production (double / frequency)
The time interval between the TS workstation (minutes / double)
MP artificial
CB 85% efficiency of the production (double / frequency)
Table 2, it is recommended to reduce the workload of the production line after the process of
Operation of ST MP CA CB No.
1 upper and dimensional inspection 0.35 2 1371.43 1165.72
2 Install the upper, and the sole lasts 1 1655.17 1406.89 0.29
3 installed innersole 1 1116.28 948.84 0.43
4 to help soften the surface of toe 0.26 1 1846.15 1569.23
5 toe wet steam 1 813.56 961.53 0.59
Help before 6 1 951.44 808.72 0.5045 machine
7 detection, hammer toe, etc. 0.40 1020 1 1200.00
Back to help and to help after 8 1 884.63 751.94 0.5426
9 1 888.89 755.56 0.54 gluing soles
10 0.42 1 1142.86 971.43 blowing hot air
11 Sulfur 0.47 1 1021.28 868.09 stereotypes
12 hammer flat type 0.48 11,000,850
13 with the heel 1 923.08 784.62 0.52
14 3 986.30 838.35 1.46 smoothing
Wax to the upper 15 1 1142.86 971.43 0.42
Brush upper 16 0.30 116,001,360
Washed 2 1142.86 971.43 0.84 17
Upper 18 0.538 1 892.19 758.36 bond
19 a good deal to help the shoe last upper 0.28 1 1714.29 1457.15
Glue to the upper 20 1 813.56 691.53 0.59
Get rid of excess glue 0.77 21 2 1246.75 1059.74
22 at the end of 0.9067 2 1058.78 899.97
23 Cooling 1 1021.28 868.97 0.47
24 0.40 112,001,020 lines cut
Detect and eliminate adhesive 25 1 842.11 715.79 0.57
Clear traces of the suture 26 0.31 1 1548.39 1316.13
Applied to the upper shoe 27 0.47 1 1021.28 868.09 milk
Off lasts 28 0.38 11263 1073.55
29 pairs of detection 0.42 1 1142.86 971.43
Coated with adhesive to the shoe lining 30 1 941.18 0.51 800
Bonding within the substrate 31 shoes 1 905.67 769.82 0.53
Screed 32 3 1133.86 963.78 1.27
1 786.89 668.86 0.61 33 scrub
Line detection and bake 34 2 2086.96 1773.92 0.46
35 painted shoes, milk (first coating) 1 905.67 769.82 0.53
36 painted shoes, milk (second coating) 0.52 1 923.08 784.62
2 979.6 832.66 0.98 37 scrub
38 with a crepe rubber sole cleaning sheet 1 761.90 647.62 0.63
39 put the shoe tree 2 880.73 748.62 1.09
40 1.09 2 880.73 748.62 with shoes
41 1 888.89 755.56 0.54 wax polishing
1 1263.16 1073.69 0.38 42 test
43 levels of correction of 0.34 1 1411.76 1073.69
Bagging 44 3 2938.78 2497.96 0.49
Total 24.9214 58
Notes:
ST standard time (minutes / double)
CA 100% efficiency of the production (double / frequency)
MP artificial
CB 85% efficiency of the production (double / frequency)
Table 3, the production capacity statistics
Number of indicators suggest the existing production line production line
1 Human 58 58
2 hours per day / shift 480 minutes 480 minutes
3 Average yield (two / day / shift) 605 672
4 standard workload (minutes / double) 25.2618 24.9214
5 hours (double) 1.29 1.45
6 labor and production capacity (double / hours) 465.12 463.45
7 hours capacity (double / h) 75.625 84
8 standard output (double / frequency) 1102.14 1117.17
9 production line efficiency 54.44% 60.15%
Table 4, the production efficiency
Efficiency improvement rate of double serial number / frequency
1 is currently 55% 0% 605.00
2 to 5% 635.25 60%
3 65% 10% 665.50
4 70% 15% 695.75
5 to 75% 20% 726.00
6 80% 25% 756.25
7 85% 30% 786.50| Updated:2011.11.11 Source: Clicks:1585
