Extending DEVS to support multiple occurrence in component-based simulation

This paper presents a new extension of the DEVS formalism that allows multiple occurrences of a given instance of a DEVS component. This paper is a follow-up to a previous short paper in which the issue of supporting a new construction called a shared component was raised, in the case of a DEVS model. In this paper, we first demonstrate, formally, that the multi-occurrence extended definition, that includes the case of shared components, is valid because any model that is built using this extended definition accepts an equivalent model built using standard DEVS. Then we recall the benefits of sharing components for modeling, and further extend this analysis to the simulation area, by investigating how shared components can help to design better simulation engines. Finally, we describe an existing implementation of a simulation software that fully supports this shared component feature, both at the modeling and simulation levels.