Process expression is one of the most useful tools to
describe the process semantics of a Petri net. However, it is usually
not easy to obtain the process expression of a Petri net directly. In
this research, a construction method is proposed to obtain the process
expressions of all kinds of Petri nets based on decomposition. With this
decomposition method, a Petri net is decomposed into a set of S-Nets.
The process properties of the decomposition nets are easy to analyze since
they are well-formed and their process expressions are easier to obtain.
With the process expressions of the decomposition nets, an algorithm to
obtain the process expression of the original Petri net is presented,
which is expressed by the synchronization shuffle operation between processes.