In simulating applications for execution on specific computing systems, the simulation performance figures must be known in a short period of time. One basic approach to the problem of reducing the required simulation time is the exploitation of parallelism. However, in parallelizing the simulation new problems arise. Due to the distributed generation of events causality errors can occur, as a result the sequence in which to process the events is essentially indeterminated.In this paper we present a model to analyse the inherent parallelism of a simulation, together with a survey of existing strategies to perform the simulation in parallel. Some extensions to this modelare discussed, resulting in reliable evaluation of the effectiveness of these strategies.