Current Trends in Continuous System Simulation

In discussing continuous system simulation languages in Chapter 6 it was pointed out that the only widely accepted’ standard’ which exists for continuous system simulation software is the CSSL specification published in 1967. Many important developments since that time have been based on the 1967 specification, but it is now recognized that software engineering principles, and other developments in hardware and software, provide opportunities for some entirely new concepts in simulation languages. New languages are already in use, such as ESL [1], COSMOS [21 and SYSMOD [3], which are in some respects fundamentally different from previous generations of simulation software and were developed using software engineering principles. The ESL simulation language, which was developed at the University of Salford in the UK with support from the European Space Agency (ESA), is of particular interest. It was based upon outline proposals produced at Salford in 1981 for a new CSSL specification [41. The ideas contained in that software specification did not define a complete simulation language and were intended to provoke discussion within the simulation community. The proposals by the Salford group were an outline and allowed flexibility and potential for contributions by others by leaving many points of detail unspecified. Although discussed at considerable length by the CSSL Committee of the Society for Computer Simulation (SCS), and by the Technical Committee TC3 of the International Association for Mathematics and Computers in Simulation (IMACS), no formal specification emerged. Many of the developments in simulation software which have taken place since 1981 are consistent with the ideas which were put forward in that outline specification.