An algorithmic analysis of simulation strategies

Each discrete event simulation language incorporates a time control procedure to conduct timing management and next event selection. Each time control procedure embodies, and thus imposes, a strategy (approach, method) for next event selection- and thereby determines the world view of a language. The three generally recognized strategies are event scheduling, activity scanning and process interaction.This paper presents algorithmic formulations of the three strategies and their modeling routines, as well as detailed discussions and comparisons of the strategies. The algorithmic formulations serve to aid understanding by describing essential aspects of the strategies while excluding implementation details which are not strategy-dependent, and which tend to detract from the essential concepts.A significant practical application of the formulations is discussed. This consists of merging the algorithms for the event scheduling and process interaction strategies into one algorithm, which then served as a model for combining GPSS and GASP IV into a simulation system providing the individual capabilities of both language, and the capability to intermix GPSS and GASP within a single model.