SIMSCRIPT II.5 Programming Language

Discrete Simulation Concepts
DESIGN TEST creation
time.a time.a time.a
eunit.a eunit.a eunit.a
predefined
attributes
p.ev.s p.ev.s p.ev.s
s.ev.s s.ev.s s.ev.s
m.ev.s m.ev.s m.ev.s
sta.a sta.a sta.a
ipc.a ipc.a ipc.a
rsa.a rsa.a rsa.a
f.rs.s f.rs.s f.rs.s
schedule
user-defined
attributes
f.materials
l.materials
n.materials
Figure 5-6. Attributes of Process Notices Created by Process Declarations
Above
5.3.8 External Processes and Events
A common validation technique used in simulation modelling is to exercise a model using event
data derived from a record of events occurring in the system under study. This is termed trace-driven
simulation. Alternatively, a collection of projected event times may, of course, be used to study
the behavior of a modelled system.
To support this technique, SIMSCRIPT II.5 provides a mechanism by which, rather than scheduling
events using statements within a program, they may be scheduled directly from event times presented
as an input data stream.
It is possible for processes and events to belong to one or both of two categories: internal or
endogenous as has so far been described, and external or exogenous, as described here. Each
class of external events or processes has, as usual, an associated routine describing actions to be
taken upon its occurrence. The difference between the two event categories lies in the manner in
which the event is scheduled. (Note that the term "event" may be taken here to also mean the
initiating event of a process.)
Events may be triggered from external input data by declaring them to be external events or
processes in a statement of the form:
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