DigSim: Procesgeoriënteerd simuleren in Java®.
Report 2000.LT.5417, Transport Technology, Logistic Engineering.
The idea of adding process-oriented simulation capabilities to a
general-purpose object-orientated programming language is not new. The
usage of the Java language is. Java has several features that are ideally
suited for the implementation of discrete-event simulation architectures.
It has an transparent structure and has multithreading capabilities that
are easy to implement. The only simulation package that has been designed
for Java is the Silk package. (ThreadTec Inc., 1998)
DigSim, following the steps of Silk, is a set of methods and classes that
greatly facilitates the creation of discrete-event simulations within the
Java programming environment. The principle of the package is based on the
process description method. Every object in a simulation has its own
process, that runs parallel to the processes of the other objects. The real
time is used as the basis for the simulated time.
The working of DigSim is explained using an implementation of a simulation of
a factory with parallel production units. The unwanted delay of the individual
processes cause unreliable results. This problem can be resolved by implementing
an executive class that has to co-ordinate all the events in a simulation, and
make sure that all the events take place at the right time.
Other improvements to DigSim could be the following: several extra animation
classes and classes for generating random numbers from distributions.
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