Population models from PEPA descriptions

Stochastic process algebras such as PEPA have enjoyed considerable success as CTMC-based system description languages for performance evaluation of computer and communication systems. However they have not been able to escape the problem of state space explosion, and this problem is exacerbated when other domains such as systems biology are considered. Therefore we have been investigating alternative semantics for PEPA models which give rise to a population view of the system, in terms of a set of nonlinear ordinary differential equations. This extended abstract gives an overview of this mapping