Book excerpt: This state-of-the-art survey in the Advances in Petri Nets series reports how various well-established and novel Petri net notions and techniques can be employed for modelling communication-based systems, with a particular focus on workflow management and business processes. The book builds on the success of a special program of the German Science Foundation (DFG) on Petri Net Technology as well as on broad participation from the international Petri net research community.