The performance evaluation was to analyze an
AMHS with a zone control scheme in avoiding all
vehicle collisions, considering the effects of the vehicle
number. In this study, the fab layout is a custom
configuration and the track option contains turntables,
turnouts, and high-speed express lanes. The behavior of
the interarrival for all stocker s from the real data set was
shown that the underlying distributions of most stockers
belong to an exponential or Weibull distribution. In
particular, the following factors were examined: the
delivery time, the transport time, the interbay throughput,
the stocker robot utilization, and the number of
crossings on turnout points and turntable points. The
results show that the number of vehicles (=80) were
able to meet the requirements. In addition, AGV-based
intrabay material handling system with a simulation
model of the photo process was investigated. The results
show that the AGVs number (=2) could meet the
requirements. Thus, the number of vehicles on inter- or
intrabay system can be determined by a simulation study.