WESTERN DIGITAL (M) SDN. BHD.
72
Reducing Wastages
in Delivering Head
Stack Assembly (HSA)
Components
W
estern Digital (M) Sdn. Bhd. (WD) is
one of the data storage industry’s
pioneers and longtime leader
operating in Petaling Jaya, Malaysia. The
company provides cost effective products and
services for their customers to collect, manage
and use digital information.
WD opens opportunities and
services for digital content
in people’s daily lives at
home, including software and
applications for handheld
devices, television and other
home entertainment devices.
Currently, WD employs thousands of
employees around the world serving to a
large number of customers from all over the
globe. WD is well-recognised globally for data
storage products. This can only be achieved
through optimising continuous process
improvement, developing competencies of
leaders and employees and committed to
open innovations.
Wastages derived from conventional
production line
Different levels of fabrication are necessary
in producing high volumes of manufactured
products. In WD, they assemble Hard
Disk Drives (HDD). They also assemble
a component of the hard drive known as
Head Stack Assembly (HSA). HDD consists
of numerous main components. They are
mounting, disk platters, circuit boards, write
head and the actuator which controls the
heads movement.
In the past, the wastages in transportation,
inventory, over production and repetition were
found in HSA packaging process. Once HSA
components were assembled, the components
were vacuumed sealed into bags and put
into carton boxes. A loss of USD50,000
worth of bags and carton boxes incurred
due to repetitive process. A total amount of
USD70,000 in wages per year was required
for the workers to fill up the HSA components
into the carton. HSA components were then
stored in the warehouse as Work-In-Progress
(WIP) components. It was later sent to HDD
factory for the next production process.
This resulted in 0.6 days lead time. An
amount of USD1.2 million of WIP components
was stored at the warehouse which would
incur losses in space and inventory cost due
to overabundance of HSA components. Over
80,000 to 100,000 of finished products were
kept in the warehouse for storage.
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WESTERN DIGITAL (M) SDN. BHD.
HSA movement before arriving to HDD production line (before LEAN)
Collaboration of LEAN in HSA and HDD
processes
With the implementation of LEAN in HSA
and HDD, eight processes were found to
be redundant. It was needless to store HSA
components in the warehouse as a new
method was being introduced. Previously,
HSA was packed into carton boxes for
packaging but with LEAN, it is placed
straight away into trolleys. A concrete Kaizen
initiative is being used by reactivating back
the microlift available in the manufacturing
floor cleanroom. From there, the trolleys are
sent to HDD via micro-lift and finally fed to
the HDD line. This initiative enables HSA
components to be sent straight to the HDD
without having to go to the warehouse. About
60 percent reduction in the conventional
processes has been achieved.
A Poke Yoke approach was also applied to
this project to prevent HSA components from
dropping with the use of new designated
trolleys. After this stage, a shock test is
conducted by placing shock sensors on the
parts to simulate possible shock risk on HSA.
A scanning system is also revised to ensure
only good HSA components are fed into the
HDD production line.
WESTERN DIGITAL (M) SDN. BHD.
74
Analysis of LEAN project in WD
From the overall analysis, lead time of 14
hours has reduced to two hours after Kaizen.
A total of USD0.5 million WIP is the result
of cost saving on inventories. Extra space
is found available for new inventories to be
placed in the warehouse. Out of the nine
conventional processes, only three value
added processes are formulated. Thus a total
amount of USD70,000 of workers’ wages per
year could be saved.
Matrix before and after LEAN project:
DESCRIPTION BEFORE
AFTER
1. Lead time
(hours)
14
2
2. Cost
saving on
inventories
(USD)
0
500,000
3. Number of
processes
9
3
4. Cost saving
on wages
(USD)
0
70,000