Apparel Online Bangladesh Magazine September Issue 2018 | Page 45

Diagram 1: Machines are arranged in
U-shaped layout, so that operators can
reach different machines much faster
maintaining a worker is higher than
cost of maintaining a machine. As
the machine utilisation is very less,
the machine productivity is also less
compared to PBU system of working.
Why stands up sewing? Stands
up workstation is mandatory for
teamwork sewing
WRONG
In a higher machine-to-operator
ratio scenario, operator needs to get
up from one machine, walk up to the
next, sit and position and then only
start work. Lot of time is wasted on
unproductive work which requires
maintaining huge WIP. To reduce
the unproductive time, ‘stands up’
workstations were introduced where
special double pedal operations
(and many other high technology
features) are present, so that team
workers can move from one machine
to another and start work instantly
without wasting much time in
settling down. The PBU system was
also vulnerable to RSI (Repetitive
Strain Injury) of upper body parts
which were eased in stands up
sewing. The stand-up sewing also
facilitates single piece movement as
successor operator actually walks up
to predecessor operator to fetch the
piece. In high intensity production
situation, the successor operator
actually bumps back to predecessor
operator and takes the pieces.
(Thus the jargon bump-back system
started)
U-shaped layout is mandatory for
teamwork in sewing
WRONG
The machine layout in teamwork can
be of any shape. However in TSS,
where one operator is supposed to
move from one machine to another,
the walking time should be bare
minimum. Therefore, the machines
are arranged in U- or C-shaped
layout, so that operators can reach
different machines much faster. In
the diagram, if an operator has to
reach from 1st to 5th machine, he/
she can just turn around and reach,
whereas in linear layout,
he/she has to walk long distances.
In case machine-to-operator ratio is
1:1, operator need not move between
one machine to another; so machine
layout does not matter. Even when
machine-to-operator ratio is more
than one, but WIP is large, then
frequency of movement of operator
from one machine to another is less;
therefore traditional linear layout
is ok.
Stand-up sewing system can be
tiring for workers
WRONG
In fact this is a mind block. On
manufacturing floor itself, there are
many operations which are done in
stand-up mode, such as ticketing,
ironing, cutting and many more.
The moment we think of sewing, we
visualise sitting operation. In reality,
double pedal control, tummy or voice
activated sewing laser alignment of
piece can deskill the sewing process
and bring comfort level as well.
Teamwork sewing helps to reduce
throughput time
RIGHT
Throughput time is a factor of SAM
value and WIP in the line. Low WIP
(or zero WIP in single piece flow)
directly cuts down the waiting time of
partly sewn pieces, which otherwise
is languishing in PBU system.
Therefore, teamwork reduces the
throughput time by reducing the
waiting time component.
On manufacturing
floor itself,
there are many
operations which
are done in stand-
up mode, such as
ticketing, ironing,
cutting and many
more. The moment
we think of sewing,
we visualise
sitting operation.
Teamwork sewing always results in
higher operator utilisation
RIGHT
Operator utilisation in PBU system
depends on balanced efficiency
of the line. In a poorly balanced
line, a significant time is wasted
by operator waiting for the pieces
from predecessor. In TSS teamwork
sewing, the line is self-balanced;
there is always a piece in every
operator’s hand. Theoretically,
operator utilisation is cent per cent.
In TSS system, operator snatches
pieces from the predecessor,
which may create quality problems
WRONG
Actually due to hands-off system,
sometimes operator leaves a
sewing operation midway (halfway)
allowing the successor operator to
complete. This may sound unrealistic
for those associated with PBU or
make-through system. In TSS, the
machines are armed with deskilling
devices to the teeth. A folder/guide
and needle positioning system
ensures that work piece is not shifted
during the changeover.
TSS in sewing results in lower
machine utilisation
RIGHT
TSS works with machine-to-operator
ratio more than once. As number
of machines are always more than
operators, and operators move from
one machine to another at any given
point of time; some machines are
always idle. Therefore, machine
utilisation is very less in TSS.
www.apparelresources.com | September 2018 | Apparel Online Bangladesh
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