In readymade garment manufacturing plants various types of sewing systems are installed. A plant owner chooses these systems depending on the production volume, product categories, and cost effectiveness of high tech machines. Among those “Progressive Bundle System” (PBS) is mostly installed sewing system till date. In this production system bundles of cut pieces (bundle of 5, 10, 20 or 30 pieces) are moved manually to feed the line. Then inside the line an operator himself drag the bundle from side table and transfer the bundle to the next operator after completion of the work.
With the advancement of the technology mechanical material transportation systems are brought in the sewing plant. An overhead material transport system, known as UPS (Unit Production System) transports cut pieces hanged in hangers (one hanger for one piece) by automated mechanical transport system. It reduces manual transportation and it has many other benefits against the progressive bundle system. This article is not to recommend one to replace this well placed progressive bundle system. When to install a new technology is depend on various factors.
A comparison between these two production systems has been drawn in the following table on the basis of production KPIs (Key Performance Indicators) to show how an UPS system (overhead hanging and sensor controlled system) is most effective over PBS.
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A comparison between these two production systems has been drawn in the following table on the basis of production KPIs (Key Performance Indicators) to show how an UPS system (overhead hanging and sensor controlled system) is most effective over PBS.
Parameters
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Progressive Bundle System (PBS)
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Unit Production System (UPS)
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Transportation
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-Manual transportation, many times helper
are hired for this bundle transportation job.
-Operators stop their work to fetch bundles.
-Less effective in terms of production
management. Resulted long response time.
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-In this system an automated mechanical
system carries pieces to each work stations.
-Easier pick up and dispose at each work
station. Resulted quick response time
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Through put time
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-Compare to UPS, through put time longer in
PBS. How much long will depend on the bundle size and no. of bundles kept in
between two operators.
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-Through put time in UPS is less compare to
PBS. But it is not the minimum time as in this system there is WIP in between
two operators.
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Direct Labour content
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- Direct labour content is high because
usually operator does tying and untying of bundles, positioning components,
pulling the bundle ticket and handling of work pieces.
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-Direct labour content is less than PBS
because an operator only sews the garment part rather than other tasks. In
this system garment parts are held by the over head hanger, so less handling
of garment components.
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WIP level
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-In PBS generally operators are asked to sew
as much pieces as they can without considering back and front operators. This
resulted piling up of work in the operations with higher work content.
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-Less WIP in between operators. As
workstation has limit of holding no. of hangers. Also after completion of
operation hangers are transported to the next operation automatically.
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Cutting
work requirement
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-As a result of High Work In Process (WIP)
is required by sewing section, cutting sections are required to perform
60-70% more than actual production can handle.
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-Lower WIP results in less cutting works. A
balanced flow of material established in between cutting and sewing line.
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Inventory Level
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-Due high WIP and higher cutting, fabrics
and trims need to stock in advance
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-Less inventory for fabric and trims.
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Excess
labour requirement
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- Usually in PBS needs more overtime works,
repair work due to some unfinished operations.
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-Plant with UPS system needs less overtime
as planning is easy in this manufacturing system.
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Reference: Various articles and websites.
Also read: Different types of production line layout (with Picture)