Combined continuous/discrete simulation: applications, techniques and tools

Beside from purely discrete event and/or continuous system simulations, there exists yet another simulation methodology that combines both classes of simulations into one. It is often possible to model one and the same system by use of completely different world views. Several papers have been written in which one particular application was modeled once by use of continuous system simulation, and once by use of discrete event simulation. Both techniques may eventually lead to the same answers. Sometimes however, one technique lends itself more easily to answering some particular questions about a system while the other is more convenient for answering some other questions about the same system. Thus, before the modeler can decide which methodology best to employ, he must know what purposes his model is going to be used for. In this paper, we want to describe applications that call for a combined continuous/discrete modeling methodology together with the techniques (concepts), that characterize this type of simulation approach. We shall also describe briefly what simulation systems are currently on the software market that can be used for this type of simulations.