The QPN formalism offers a convenient and powerful notation for the combined description of qualitative and quantitative aspects of a system. This notation is very suitable for PN as well as QN analysts. QPNs especially simplify the description of scheduling aspects. It is, e.g., a very difficult task to define an FCFS queue with GSPN elements, if an upper bound of the token number is not known a priori.
Apart from their expressive power, QPNs provide a well-founded theoretical basis for the development of a reasonable procedure for combining qualitative and quantitative analysis also exploiting efficient analysis techniques from PN theory as shown in Sect. 6.
Enhancement of the QPN formalism by inhibitor arcs and different priority levels of immediate transitions, like in the definition of GSPNs, is straightforward, although this would complicate carrying properties of the CPN over to the timed net.
Tool support for modeling and analysis of QPNs exhibiting no immediate queueing places is also available [8]. Here templates for timed queueing places are offered which have to be completed by service specific parameters specified by the user.
Future developments of the QPN formalism are directed to the integration of hierarchical description techniques.