The single automated cells constitute the most
common system in the hard disk drive manufacturing
system industry. This cell operates independently of other
workstations in the factory [1]. It composed of a fully
automated machine which can be of unattended operation
for a longer period of time. This type of machine usually
equips with an automatic pallet change (APC) and
automatic tool change (ATC). The work-parts are kept at
the part storage subsystem and will be automatically
transferred and positioned to the machine. Due to the fact
that this machine does not require continuous attention
from an operator during its semi-automatic machine
cycle, the operator can be assigned more than one
machine to operate. A worker assignment task normally
is handled heuristically particularly at the cell
implementation level. Matching of worker experiences to
a production requirement is the most common practices.
This can lead to an unbalance workload, non utilization of
machine, and low efficiency. The company may not be
able to maximize utilization of workers and machine [2].