unless they strive for necessary improvements that will
lead to productivity growth, more rational usage of allnatural resources, and cost reduction. In most cases
these companies do not see the necessity for changes
in management, capacity, and planning, which are
negatively impacting many apparel industries today
(Karthik et al. 2017).
The disruption in textile and apparel industry triggered by digital transformation or disruptive technologies of industry 4.0 is enormous (Bongomin, Gilibrays
Ocen, Oyondi Nganyi, Musinguzi, & Omara 2020). It
is very likely that the RMG industry will undergo profound changes over the next few years. Smart Clothes,
i.e., clothing characterized not only by its traditional
protective and representational functions, but also by
technological and digital features, have evolved as
a promising opportunity for the RMG industry, and
are known as fashion 4.0 or apparel 4.0 (Behr 2018;
Bertola & Teunissen 2018).
2.2 Garment manufacturing systems
An apparel or garment production system is an integration of materials handling, production processes,
personnel, and equipment that direct workflow and
generate finished products (Babu 2012). There are
three types of apparel production system that are
widely adopted in garment industry: (1) group or modular production system (Sudarshan & Rao 2014); (2)
progressive bundle production system; and (3) unit
production system. In a modular production system,
operations are done in contained and manageable work
cells that include a number of specialized resources,
such as an empowered work team, equipment, and
work to be executed. This production system has
achieved the success of flexibility. However, very high
initial capital costs and investment in training are still
the major limitations to its adaptation to most apparel
industries.
The progressive bundle production system, normally referred to as the conventional production system, is still the most commonly installed production
system to date in terms of garment production systems because of its cost effectiveness on high-tech
machines. The operation in this system involves moving bundles of cut pieces manually to feed the line.
Whereby, the operator inside the line drags the bundles by him/herself from the table and transfers the
bundle to the next operator after completing his/her
task. The major problem with the progressive bundle system is the tendency of accumulating a very
large inventory which imposes the extra cost of controlling and handling inventory. In order to overcome
the limitation of material handling in the progressive bundle system, a new system called the unit
production system was developed. In this system, an
overhead transporter is used to move the garment
from one workstation to another. This system basically improves material handling in the assembly line.
The success of the unit production system is that it
improves the production lead times, productivity, and
space utilization. However, this production system is
extremely expensive. In general, the trade-off of these
production systems depends on the production volume, product categories, and the cost effectiveness of
high-tech machines (Karthik et al. 2017).
2.3 Industrial engineering tools
2.3.1 ABC classification
Traditionally, ABC analysis has been used to classify
various inventory items into three categories: A, B,
and C, based on the criterion of dollar volume. In
the current globalized hyper-responsive business environment, a single criterion is no longer adequate to
guide the management of inventories, and therefore
multiple criteria have to be considered (Sibanda & Pretorius 2011). Other criteria that can be considered for
ABC analysis include lead time, item criticality, durability, scarcity, reparability, stockability, commonality,
substitutability, the number of suppliers, mode and
cost of transportation, the likelihood of obsolescence
or spoilage, and batch quantities imposed by suppliers. Consequently, ABC analysis has been adopted
amongst researches to make decision on the selection of products, machines, production lines, etc. For
instance, Pinho and Leal (2007) used ABC analysis to
prioritize a production system for their study based on
productivity per day criterion. Therefore, in the current situation, ABC analysis tool was also adopted to
prioritize the product model and assembly line to be
used in this study.
2.3.2 Process mapping
Process mapping is an exercise of identifying all the
steps and decisions in a process in a diagrammatic
form, with a view to continually improve that process. In literature, two commonly used types of process
mapping are process flowchart (outline process map)
and deployment charts. The former is useful for capturing the initial detail of the process. For instance, Kursun and Kalaoglu (2009), Kitaw et al. (2010), Bahadır
(2011), and Yemane, Haque, and Haque (2017) used
a process flowchart as a conceptual model in their
simulation study with the aim of analyzing and understanding the current state of the studied system. The
latter not only provides a basic overview but also shows
who does what along with the interactions between
people and departments. This one has been used as
a stand-alone method amongst studies for process
improvement. Uddin (2015) improved the production
process using value stream mapping as a stand-alone
method. Since then, the present study adopted process
mapping as a tool for conceptual modeling; the process
flowchart method was best suited for this study.
2.3.3 Fishbone diagram
Cause-and-effect diagram (fishbone diagram) is
another method that has been widely used in studies
(Barton 2004). It is an analysis tool that provides a systematic way of looking at effects (performance measures) and the causes (factors or independent variables)
77
lead to productivity growth, more rational usage of allnatural resources, and cost reduction. In most cases
these companies do not see the necessity for changes
in management, capacity, and planning, which are
negatively impacting many apparel industries today
(Karthik et al. 2017).
The disruption in textile and apparel industry triggered by digital transformation or disruptive technologies of industry 4.0 is enormous (Bongomin, Gilibrays
Ocen, Oyondi Nganyi, Musinguzi, & Omara 2020). It
is very likely that the RMG industry will undergo profound changes over the next few years. Smart Clothes,
i.e., clothing characterized not only by its traditional
protective and representational functions, but also by
technological and digital features, have evolved as
a promising opportunity for the RMG industry, and
are known as fashion 4.0 or apparel 4.0 (Behr 2018;
Bertola & Teunissen 2018).
2.2 Garment manufacturing systems
An apparel or garment production system is an integration of materials handling, production processes,
personnel, and equipment that direct workflow and
generate finished products (Babu 2012). There are
three types of apparel production system that are
widely adopted in garment industry: (1) group or modular production system (Sudarshan & Rao 2014); (2)
progressive bundle production system; and (3) unit
production system. In a modular production system,
operations are done in contained and manageable work
cells that include a number of specialized resources,
such as an empowered work team, equipment, and
work to be executed. This production system has
achieved the success of flexibility. However, very high
initial capital costs and investment in training are still
the major limitations to its adaptation to most apparel
industries.
The progressive bundle production system, normally referred to as the conventional production system, is still the most commonly installed production
system to date in terms of garment production systems because of its cost effectiveness on high-tech
machines. The operation in this system involves moving bundles of cut pieces manually to feed the line.
Whereby, the operator inside the line drags the bundles by him/herself from the table and transfers the
bundle to the next operator after completing his/her
task. The major problem with the progressive bundle system is the tendency of accumulating a very
large inventory which imposes the extra cost of controlling and handling inventory. In order to overcome
the limitation of material handling in the progressive bundle system, a new system called the unit
production system was developed. In this system, an
overhead transporter is used to move the garment
from one workstation to another. This system basically improves material handling in the assembly line.
The success of the unit production system is that it
improves the production lead times, productivity, and
space utilization. However, this production system is
extremely expensive. In general, the trade-off of these
production systems depends on the production volume, product categories, and the cost effectiveness of
high-tech machines (Karthik et al. 2017).
2.3 Industrial engineering tools
2.3.1 ABC classification
Traditionally, ABC analysis has been used to classify
various inventory items into three categories: A, B,
and C, based on the criterion of dollar volume. In
the current globalized hyper-responsive business environment, a single criterion is no longer adequate to
guide the management of inventories, and therefore
multiple criteria have to be considered (Sibanda & Pretorius 2011). Other criteria that can be considered for
ABC analysis include lead time, item criticality, durability, scarcity, reparability, stockability, commonality,
substitutability, the number of suppliers, mode and
cost of transportation, the likelihood of obsolescence
or spoilage, and batch quantities imposed by suppliers. Consequently, ABC analysis has been adopted
amongst researches to make decision on the selection of products, machines, production lines, etc. For
instance, Pinho and Leal (2007) used ABC analysis to
prioritize a production system for their study based on
productivity per day criterion. Therefore, in the current situation, ABC analysis tool was also adopted to
prioritize the product model and assembly line to be
used in this study.
2.3.2 Process mapping
Process mapping is an exercise of identifying all the
steps and decisions in a process in a diagrammatic
form, with a view to continually improve that process. In literature, two commonly used types of process
mapping are process flowchart (outline process map)
and deployment charts. The former is useful for capturing the initial detail of the process. For instance, Kursun and Kalaoglu (2009), Kitaw et al. (2010), Bahadır
(2011), and Yemane, Haque, and Haque (2017) used
a process flowchart as a conceptual model in their
simulation study with the aim of analyzing and understanding the current state of the studied system. The
latter not only provides a basic overview but also shows
who does what along with the interactions between
people and departments. This one has been used as
a stand-alone method amongst studies for process
improvement. Uddin (2015) improved the production
process using value stream mapping as a stand-alone
method. Since then, the present study adopted process
mapping as a tool for conceptual modeling; the process
flowchart method was best suited for this study.
2.3.3 Fishbone diagram
Cause-and-effect diagram (fishbone diagram) is
another method that has been widely used in studies
(Barton 2004). It is an analysis tool that provides a systematic way of looking at effects (performance measures) and the causes (factors or independent variables)
77