6 Lpsoh & Roruhg 3 Hwul 1 Hwv

Petri Nets (P-nets) are widely used in many fields. Because of their simple working, many formal analysis and synthesis methods are applicable to them, and furthermore P-net-based software tools can be implemented with relative ease. However, P-nets are inconvenient to use in very large and complex applications. Colored Petri Nets (CP-nets) provide much more convenience and compactness than P-nets. The price is that greater efforts are required to implement CP-net-based software tools, and that most formal analysis and synthesis methods are not applicable to them. We propose Simple Colored Petri Nets (SCP-nets) as a promising trade-off between the simplicity of P-nets and the convenience of CP-nets. SCP-nets are similar to CP-nets, but user-defined data types must be enumerative. Despite this restriction, SCP-nets provide much more convenience than P-nets. Since operations upon enumerative types are most naturally defined by listing argument-result pairs, SCP-net-based software tools can be implemented much more easily than CP-net-based ones, because no general programming language is needed to define types and operations. Moreover, SCP-nets seem to be more amenable to formal analysis and synthesis methods than CP-nets, as we are investigating through some ongoing research. Another valuable feature of SCP-nets is that, unlike CP-nets, their types can be organized in hierarchies.