Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering
Transport Technology / Logistic Engineering

S.A. Harteveld DigSim: Procesgeoriënteerd simuleren in Java®.
Computer program, 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.

Reports on Logistic Engineering (in Dutch)
Modified: 2001.01.05; , TU Delft / 3mE / TT / LT.