1. An availability evaluating system for obtaining an availability of a semiconductor manufacturing line in which it is virtually
assumed that a unit group having one or more tool units are serially connected in time series according to a processing event,
the system comprising:
a first unit configured to calculate an incidence probability Xi (i=1 to k) in combination by applying a probability of tool
operation and a probability of tool stoppage to all combinations “k” in which at least a line fabrication availability is
not zero, of the combinations of operation and stoppage of tools each configuring the semiconductor manufacturing line and
by obtaining a product of the probabilities of all the tools; and
a second unit configured to, when a product between an incidence probability Xi of a combination and a fabrication availability
Yi of the combination is defined as a probability converted fabrication availability with respect to each of the combinations,
calculate as a line availability a value of Q=Σ(i=1 to k)X1×Y1/F obtained by dividing a sum of probability converted fabrication availabilities of the combinations by a fabrication availability
F determined during a 100% availability.
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