John Francis Lubin

The purpose of this paper is to present a comparison of some computer simulation languages and of some of the packages by which each is implemented. Some considerations involved in comparing software packages for digital computers are discussed in Part I. The issue is obvious: users of digital computers must choose from available languages or write their own. Substantial costs can occur, particularly in training, implementation and computer time if an inappropriate language is chosen. More and more computer simulation languages are being developed: comparisons and evaluations of existing languages are useful for designers and implementers as well as users. The second part is devoted to computer simulation and simulation languages. The computational characteristics of simulation are discussed with special attention being paid to a distinction between continuous and discrete change models. Part III presents a detailed comparison of six simulation languages and packages: SIMSCRIPT, CLP, CSL, GASP, GPSS and SOL. The characteristics of each are summarized in a series of tables. The implications of this analysis for designers of languages, for users, and for implementers are developed. The conclusion of the paper is that the packages now available for computer simulation offer features which none of the more general-purpose packages do and that analysis of strengths and weaknesses of each suggests ways in which both current and future simulation languages and packages can be improved.