In: Math. Struct. in Comp. Science (2005), vol. 15, Cambridge Univ. Press, pages 1-15. 2005.
Abstract: In order to model the behaviour of open concurrent systems by means of Petri nets, we introduce open Petri nets, a generalisation of the ordinary model where some places, designated as open, represent an interface between the system and the environment. Besides generalising the token game to reflect this extension, we define a truly concurrent semantics for open nets by extending the Goltz-Reisig process semantics of Petri nets.