Line Balancing for Improving Apparel Production by Operator Skill Matrix

International Journal of Science, Technology and Society
2015; 3(4): 101-106
Published online May 29, 2015 (http://www.sciencepublishinggroup.com/j/ijsts)
doi: 10.11648/j.ijsts.20150304.11
ISSN: 2330-7412 (Print); ISSN: 2330-7420 (Online)
Line Balancing for Improving Apparel Production by
Operator Skill Matrix
Md. Mazharul Islam1, *
, Md. Tanjim Hossain1
, Mohammad Abdul Jalil2
, Elias Khalil3
1
Department of Textile Engineering, Northern University of Bangladesh, Dhaka, Bangladesh
2
Department of Textile Engineering, Mawlana Bhashani Science and Technology University, Tangail, Bangladesh
3
Department of Textile Engineering, World University of Bangladesh, Dhaka, Bangladesh
Email address:
mazh999@gmail.com (Md. M. Islam), tanjimseu@yahoo.com (Md. T. Hossain), jalil.mbstu@gmail.com (M. A. Jalil),
eliaskhalil52@gmail.com (E. Khalil)
To cite this article:
Md. Mazharul Islam, Md. Tanjim Hossain, Mohammad Abdul Jalil, Elias Khalil. Line Balancing for Improving Apparel Production by
Operator Skill Matrix. International Journal of Science, Technology and Society. Vol. 3, No. 4, 2015, pp. 101-106.
doi: 10.11648/j.ijsts.20150304.11
Abstract: In this modern world, fashion & styles are changing frequently. The emergence of fast changes in fashion has given
rise to shorten production cycle time in the garment industry. To meet the dynamic customer demands of momentous quantities in
shorten lead time, assembly line production systems are used, where the garment components are assembled into a finished
garment through a sub-assembly process. So in the era of product customization, the optimal usage of resources especially the
available facilities & operators who are adding the value of product is important. Therefore the assembly line has to be planned in
much more flexible way. This paper deals with the maximum utilization of manpower in labor intensive assembly lines. The
objective is to accurately delegate workers to the various operations required to complete the product based on their skill &
experience so as to achieve the highest level of productivity and delivery as per planned target. The experimental result showed
meaningful improvement in productivity as compared to the existing system.
Keywords: Line Balancing, Skill Matrix, Assembly Line, Apparel Production
1. Introduction
As a supply chain of textile industry, garment industry is
one of the major industries of the world. The production
process of garments is separated into four main phases:
designing/ clothing pattern generation, fabric spreading &
cutting, sewing and ironing & packing. The most critical
phase is sewing phase [1]. As the sewing is the heart of
apparel industry, we have to design the sewing line properly
so as to achieve the best output at maximum efficiency.
Apparel is a mass production system. Assembly line
production systems are developed to meet the requirements
of mankind, which continue to grow day by day [2]. The
demand for greater product variability and shorter life cycles
has caused traditional production methods to be replaced
with assembly lines [3]. Assembly line is an industrial
arrangement of machines, equipments and workers for
continuous flow of work pieces in mass production operation.
Manufacturing a product in an assembly line requires
partitioning the total amount of work into a set of elementary
operations called tasks [4]. Tasks are assigned to operators
depending on constrains of different labor skill levels. Finally,
several workstations in sequence are formed as a sewing line
[5]. The sewing process includes a set of work stations, at
each of which a specific task is carried out in a restricted
sequence, with hundreds of employees and thousands of
bundles of sub-assemblies producing different style
simultaneously [6]. Therefore this process is of critical
importance and needs to be planned more carefully [7]. As a
consequence, good line balancing with small stocks in the
sewing line has to be drawn up to increase the efficiency and
quality [7-9]. So the aim of assembly line balancing in
sewing line is to assign tasks to the workstations, so that the
machines of the workstation can perform the assigned task
with a balanced loading with different labor skill levels [5].
2. Literature Review
A line is defined as a group of operators under the control of
one production supervisor [10]. Balancing is the technique of
maintaining the same level of inventory at each and every

102 Md. Mazharul Islam et al.: Line Balancing for Improving Apparel Production by Operator Skill Matrix
operation at any point of time to meet the production target and
to produce garments of acceptable quality [10]. Assembly line
balancing (ALB) is a managerial technique and can be applied
to balance production flow lines [11-12]. Line balancing is the
distribution of work on the line in such a way that everyone
gets the same amount of work in terms of time [13]. In practice,
a perfect balance could not be achieved but we can improve
the situation by using proper technique.
The assembly line balancing problem was first introduced
by Bryton in his graduate thesis. In his study, he accepted the
amount of workstations as constant, the workstation times as
equal for all stations and work tasks as moving among the
workstations [14]. The first article was published in 1955 by
Salveson [15]. He developed a 0-1 integer programming
model to solve the problem. This heuristic method was
developed by Helgeson and Birnie of the General Electric
Company in 1961 COMSOAL (Computer Method of
Sequencing Operations for Assembly Lines) was first used by
Arcus in 1966 as a solution approach to the assembly line
balancing problem [16,17]. Bartholdi (1993) was the first to
address the Two-sided Assembly Line Balancing Problem
with the objective of minimizing the number of stations by
applying a simple assignment rule. Liu & Chen (2002)
presented a Genetic Algorithm approach for assembly
planning involving various objectives, such as minimizing
cycle time, maximizing workload smoothness, minimizing
the frequency of tool change, minimizing the number of tools
and machines used and minimizing the complexity of
assembly sequences [18-19]. Helgeson ve Birnie (1961)
developed the “Ranked Positional Weight Technique” in
which operation having the largest ranged weight is assigned
to the first workstation, and other operations are assigned to
workstations in accordance with their ranked positional
weight value [16]. Abdolmajid Yolmeh et al. (2012) proposed
a hybrid genetic algorithm to solve the assembly line
balancing problem [20].
Operator's Skill Inventory is the database which maintains
the record of each operator, who can do what type of
operation and at what rating. It is very important to keep this
database updated as over the time, operator acquire skills for
most of the new operations as well as improve performance
in existing operations [21].With the use of skill matrix an
engineer's or line supervisors needs very list time to find out
and select most efficient operator for a particular operation
from the pull of operation. It helps the line supervisor for
balancing the line with particular skilled operators according
to the work content [21].
There are so many researches going on in the field of
assembly line balancing. Various methods are used for
balancing sewing lines which are discussed in the above
section. We use operator skill matrix for better allocation of
operator throughout the sewing line to get maximum output.
3. Materials and Methodology
In this experiment, 100% cotton Jacket was considered.
Total 30 sewing machines were used where number of plain,
over lock and flat lock machines was 13, 11, and 6
respectively.
In order to balance a production line in sewing floor a line
was chosen & necessary data was accumulated from the line.
First the garment was analyzed and operational bulletin or
breakdown was created with process sequence, operational
description & machine requirements (Table 1). Then workers
were placed to different work stations based on operation &
machine types and a standard minute for each job was given
to the operators (allocated SMV) (Table 1). After one day we
calculate the output & found that we didn’t get the desired
output. To found out the problem, we calculated individual
workers performed SMV by work study. After that workers
individual efficiency & output at individual efficiency was
calculated and then saw that efficiencies varies dramatically
due to unplanned layout (Table 1). So to balance the line we
have to rearrange the operators within the line. To do this,
first machine-wise breakdown (Table 2 to Table 7) was done
and workers are reallocated based on two assumptions: a)
operators are only be allocated depending on the machine
type that he/she can operate; b) allocation is also depend on
operation type that he/she can perform. After fulfilling above
two conditions we rearranged operators based on SMV.
Higher the SMV, higher should be the efficiency % as we
know where the workload is high, we need higher efficient
worker. After total rearrangement, we again calculated the
output (Table 8). We observed that productivity is increased
but not up to the theoretical productivity. In some process,
huge bottleneck was appeared. So to improve productivity
we introduced another worker to the bottleneck operation by
dividing the workload between two workers (Table 9).
Finally we got satisfactory productivity.
4. Experimental Data
Operational Bulletin of Jacket before and after
arrangement, Breakdown of different machines before and
after rearrangement along with comparison of productions
are shown below in different tables.
Table 1. Operational Bulletin of Jacket before arrangement.
SL Process Name Name M/c Type
Performed
SMV
Allocated
SMV
Output @
100% eff
Efficiency %
Output @
performed
efficiency %
1 Back part panel join Jarna O/L 0.64 0.62 96.77 96 93.26
2 Back panel ts tc Naher F/L 0.35 0.3 200.00 87 173.08
3 Left and right panel join Hasina O/L 1.72 0.62 96.77 36 34.95
4 Left and right panel join Eima O/L 1.28 0.62 96.77 48 46.88
5 Left and right panel ts and tc Mena F/L 0.62 0.55 109.09 89 97.30

International Journal of Science, Technology and Society 2015; 3(4): 101-106 103
SL Process Name Name M/c Type
Performed
SMV
Allocated
SMV
Output @
100% eff
Efficiency %
Output @
performed
efficiency %
6 Front part panel join & tc Ronju O/L 0.78 0.5 120.00 64 76.60
7 Front part panel ts & tc Monzilla L/S 0.53 0.3 200.00 57 113.92
8 Left & right panel join Amina O/L 0.82 0.62 96.77 76 73.47
9 Left and right panel join Sahina O/L 0.79 0.62 96.77 78 75.95
10 Left and right panel ts & tc Nurbanu F/L 0.53 0.55 109.09 103 112.50
11 Shoulder panel join Lima O/L 0.94 0.43 139.53 46 63.60
12 Shoulder panel ts Alima F/L 0.88 0.42 142.86 48 68.18
13 Shoulder join Rojina O/L 0.92 0.59 101.69 64 65.45
14 Sleeve panel make Morina O/L 0.64 0.45 133.33 70 93.26
15 Sleeve panel top stitch & tc Sokina F/L 0.47 0.49 122.45 104 126.76
16 Sleeve hem Momina F/L 0.42 0.3 200.00 71 141.73
17 Collar make Pervin L/S 0.79 0.63 95.24 80 75.95
18 Collar twill tape attach Rebeka L/S 0.26 0.22 272.73 85 230.77
19 Collar serving Roksana O/L 0.43 0.39 153.85 90 138.46
20 Zipper twill tape make Sabina L/S 0.88 0.42 142.86 48 68.44
21 Zipper twill tape attach Rojina L/S 0.87 0.5 120.00 57 68.97
22 Zipper holding tuck Bobita L/S 0.66 0.3 200.00 45 90.91
23 Zipper patch attach at bottom Shahanara L/S 0.45 0.57 105.26 127 133.33
24 Collar join Sabina L/S 1.77 0.78 76.92 44 33.90
25 Collar join Shahila L/S 1.99 0.78 76.92 39 30.15
26 Zipper tuck with body Naher L/S 0.36 0.42 142.86 118 168.22
27 Zipper join with left side Halima L/S 0.58 0.5 120.00 86 103.45
28 Zipper join right side Orchona L/S 0.76 0.69 86.96 90 78.60
29 Zipper facing join Beauty L/S 0.66 0.5 120.00 76 90.91
30 Zipper facing o/l Sharmin O/L 0.36 0.3 200.00 83 165.14
Max Theoretical output 76.92 practical output 30 pcs
Table 2. Breakdown of Plain machines before rearrangement.
SL Process Name Name M/c Type Performed SMV Efficiency
7 Front part panel ts & tc Monzilla L/S 0.53 57%
17 Collar make Pervin L/S 0.79 80%
18 Collar twill tape attach Rebeka L/S 0.26 85%
20 Zipper twill tape make Sabina L/S 0.88 48%
21 Zipper twill ta[e attach Rojina L/S 0.87 57%
22 Zipper holding tuck Bobita L/S 0.66 45%
23 Zipper patch attach at bottom Shahanara L/S 0.45 127%
24 Collar join Sabina L/S 1.77 44%
25 Collar join Shahila L/S 1.99 39%
26 Zipper tuck with body Naher L/S 0.36 118%
27 Zipper join with left side Halima L/S 0.58 86%
28 Zipper join right side Orchona L/S 0.76 90%
29 Zipper facing join Beauty L/S 0.66 76%
Table 3. Breakdown of Plain machines after rearrangement.
SL Process Name Name M/c Type Performed SMV Efficiency
18 Collar twill tape attach Shahila L/S 0.26 39%
26 Zipper tuck with body Sabina L/S 0.36 44%
23 Zipper patch attach at bottom Bobita L/S 0.45 45%
7 Front part panel ts & tc Sabina L/S 0.53 48%
27 Zipper join with left side Monzilla L/S 0.58 57%
22 Zipper holding tuck Rojina L/S 0.66 57%
29 Zipper facing join Beauty L/S 0.66 76%
28 Zipper join right side Pervin L/S 0.76 80%
17 Collar make Rebeka L/S 0.79 85%
21 Zipper twill tape attach Halima L/S 0.87 86%
20 Zipper twill tape make Orchona L/S 0.88 90%
24 Collar join Naher L/S 1.77 118%
25 Collar join Shahanara L/S 1.99 127%

Table 4. Breakdown of Overlock machines before rearrangement.
SN Process Name Name M/c Type Performed SMV Efficiency
1 Back part panel join Jarna O/L 0.64 96%
3 Left and right panel join Hasina O/L 1.72 36%
4 Left and right panel join Eima O/L 1.28 48%
6 Front part panel join & tc Ronju O/L 0.78 64%
8 Left & right panel join Amina O/L 0.82 76%
9 Left and right panel join Sahina O/L 0.79 78%
11 Shoulder panel join Lima O/L 0.94 46%
13 Shoulder join Rojina O/L 0.92 64%
14 Sleeve panel make Morina O/L 0.64 70%
19 Collar serving Roksana O/L 0.43 90%
30 Zipper facing o/l Sharmin O/L 0.36 83%
Table 5. Breakdown of Overlock machines after rearrangement.
30 Zipper facing o/l Hasina O/L 0.36 36%
19 Collar serving Lima O/L 0.43 46%
14 Sleeve panel make Eima O/L 0.64 48%
1 Back part panel join Ronju O/L 0.64 64%
6 Front part panel join & tc Rojina O/L 0.78 64%
9 Left and right panel join Morina O/L 0.79 70%
8 Left & right panel join Amina O/L 0.82 76%
13 Shoulder join Sahina O/L 0.92 78%
11 Shoulder panel join Sharmin O/L 0.94 83%
4 Left and right panel join Roksana O/L 1.28 90%
3 Left and right panel join Jarna O/L 1.72 96%
Table 6. Breakdown of Flat lock machines before rearrangement.
2 Back panel ts tc Naher F/L 0.35 87%
5 Left and right panel ts and tc Mena F/L 0.62 89%
10 Left and right panel ts & tc Nurbanu F/L 0.53 103%
12 Shoulder panel ts Alima F/L 0.88 48%
15 Sleeve panel top stitch & tc Sokina F/L 0.47 104%
16 Sleeve hem Momina F/L 0.42 71%
Table 7. Breakdown of Flat lock machines after rearrangement.
SN Process Name Name m/c Performed SMV Efficiency
2 Back panel ts tc Alima F/L 0.35 48%
16 Sleeve hem Momina F/L 0.42 71%
15 Sleeve panel top stitch & tc Naher F/L 0.47 87%
10 Left and right panel ts & tc Mena F/L 0.53 89%
5 Left and right panel ts and tc Nurbanu F/L 0.62 103%
12 Shoulder panel ts Sokina F/L 0.88 104%
Table 8. Operational Bulletin of Jacket after rearrangement.
SN Process Name Name M/c Type Performed SMV Efficiency % Output @ performed efficiency
1 Back part panel join Ronju O/L 0.64 48 46.45
2 Back panel ts tc Alima F/L 0.35 48 96.00
3 Left and right panel join Jarna O/L 1.72 96 92.90
4 Left and right panel join Roksana O/L 1.28 90 87.10
5 Left and right panel ts and tc Nurbanu F/L 0.62 71 77.45
6 Front part panel join & tc Rojina O/L 0.78 64 76.80
7 Front part panel ts & tc Sabina L/S 0.53 44 88.00
8 Left & right panel join Amina O/L 0.82 76 73.55
9 Left and right panel join Morina O/L 0.79 70 67.74
10 Left and right panel ts & tc Mena F/L 0.53 87 94.91
11 Shoulder panel join Sharmin O/L 0.94 83 115.81

International Journal of Science, Technology and Society 2015; 3(4): 101-106 105
12 Shoulder panel ts Sokina F/L 0.88 89 127.14
13 Shoulder join Sahina O/L 0.92 78 79.32
14 Sleeve panel make Eima O/L 0.64 64 85.33
15 Sleeve panel top stitch & tc Naher F/L 0.47 103 126.12
16 Sleeve hem Momina F/L 0.42 104 208.00
17 Collar make Rebeka L/S 0.79 86 81.90
18 Collar twill tape attach Shahila L/S 0.26 39 106.36
19 Collar serving Lima O/L 0.43 46 70.77
20 Zipper twill tape make Orchona L/S 0.88 48 68.57
21 Zipper twill tape attach Halima L/S 0.87 57 68.40
22 Zipper holding tuck Rojina L/S 0.66 45 90.00
23 Zipper patch attach at bottom Bobita L/S 0.45 85 89.47
24 Collar join Naher L/S 1.77 118 90.77
25 Collar join Shahanara L/S 1.99 127 97.69
26 Zipper tuck with body Sabina L/S 0.36 57 81.43
27 Zipper join with left side Monzilla L/S 0.58 76 91.20
28 Zipper join right side Pervin L/S 0.76 90 78.26
29 Zipper facing join Beauty L/S 0.66 80 96.00
30 Zipper facing o/l Hasina O/L 0.36 36 72.00
Practical output after rearrangement
Table 9. Final Practical output after sharing of work.
1 Back part panel join Raju O/L 0.64 48 46.45
1 Back part panel join Ronju O/L 0.64 48 46.45
2 Back panel ts tc Alima F/L 0.35 48 96.00
3 Left and right panel join Jarna O/L 1.72 96 92.90
4 Left and right panel join Roksana O/L 1.28 90 87.10
5 Left and right panel ts and tc Nurbanu F/L 0.62 71 77.45
6 Front part panel join & tc Rojina O/L 0.78 64 76.80
7 Front part panel ts & tc Sabina L/S 0.53 44 88.00
8 Left & right panel join Amina O/L 0.82 76 73.55
9 Left and right panel join Morina O/L 0.79 70 67.74
10 Left and right panel ts & tc Mena F/L 0.53 87 94.91
11 Shoulder panel join Sharmin O/L 0.94 83 115.81
12 Shoulder panel ts Sokina F/L 0.88 89 127.14
13 Shoulder join Sahina O/L 0.92 78 79.32
14 Sleeve panel make Eima O/L 0.64 64 85.33
15 Sleeve panel top stitch & tc Naher F/L 0.47 103 126.12
16 Sleeve hem Momina F/L 0.42 104 208.00
17 Collar make Rebeka L/S 0.79 86 81.90
18 Collar twill tape attach Shahila L/S 0.26 39 106.36
19 Collar serving Lima O/L 0.43 46 70.77
20 Zipper twill tape make Orchona L/S 0.88 48 68.57
21 Zipper twill tape attach Halima L/S 0.87 57 68.40
22 Zipper holding tuck Rojina L/S 0.66 45 90.00
23 Zipper patch attach at bottom Bobita L/S 0.45 85 89.47
24 Collar join Naher L/S 1.77 118 90.77
25 Collar join Shahanara L/S 1.99 127 97.69
26 Zipper tuck with body Sabina L/S 0.36 57 81.43
27 Zipper join with left side Monzilla L/S 0.58 76 91.20
28 Zipper join right side Pervin L/S 0.76 90 78.26
29 Zipper facing join Beauty L/S 0.66 80 96.00
30 Zipper facing o/l Hasina O/L 0.36 36 72.00
Final Practical output (after sharing of work)
Table 10. Comparison of production before & after study.
Parameter Before Rearrangement After Rearrangement After sharing of work
No of m/c 30 30 31
No of manpower 30 30 31
Output per hr 30 46 68

5. Results & Discussion
Changing from traditional layout to balanced layout model
by proper allocation of workers, there are considerable
improvements have moved towards us. With final scenario,
the best performance results were obtained as summarized in
table 10. The average hourly output of the system increased
from 30 to 68 pieces. With reference to scenario, it can be said
that the balance of sewing line seems appropriate for all
performance measures.
6. Conclusion
Skill matrix helps in allocating right person for the right job
which helps in achieving desired performance level. It keeps
record of all operations an operator had done in the past and
efficiency level in each operation. Engineers / line supervisors
need minimum time to find and select most efficient operators
for an operation from the pull of operators. For line balancing,
operators can be selected according to work content. When
someone is absent, supervisor can easily find suitable person
from the skill matrix table and replace. To analyses the skill
availability and distribution throughout the factory. This can
be compared with the skill requirement for a particular time
period and shortage/excess skill availability to achieve at the
training requirement. So productivity can be achieved by
allocating skill & semi-skilled workers to the right place and
unskilled operator should be trained properly.
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