| Summary: | 碩士 === 國立交通大學 === 工業工程研究所 === 83 === The system throughput of the wafer fabrication is limited by
the machine capacity and the random variations from the machine
breakdowns. Therefore, the main goal of the production activity
control is to fully utilize the capacity of the constraint
resource. And the secondary goal is to low down the WIP level
in the shop floor and the production flow time. To design the
control policy for a wafer fabrication factory, this thesis
first constructs the policy selection analysis. It identifies
the basic factors of the production control policy, including
the utilization rate of capacity constraint resource(CCR),
reentry characteristies, WIP control, and machine breakdown.
According to these factors, twelve material release rules are
studied and compared to find out the relationships and
differences. The results show that the starvation avoidance
(SA) rule, developed by Glassey & Resende[4], meets the control
goals the most. As a result, this thesis try to combine the
concepts of the SA rule and the WIP Control rule to develop the
production activity control model for wafer fabrication
factory. For the material release, this control model establish
the safety WIP level, the WIP threshold values between two
consecutive operation layers, and the cumulative release
threshold values to control the material release process. For
the dispatching, this model considers whether or not the
operation station is the CCR, and the CCR is in starvation
state or not. Besides, the dispatching model considers the
balancing of the WIP level for each operation layer of every
product. It also considers the priority difference among
orders. The experience studies show that the capacity of the
CCR is fully utilized when applying the developed model. The
results also show that the model has high performance in mean
value and standard deviation in the following measures : the
throughput rate, the flow time of products, the queue time, and
the WIP level.
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