1. A method of synthesizing a message sequence chart (MSC) from a communicating finite-state machine (CFSM), comprising: transforming the CFSM to a Petri net model; executing by a computer processor to generate a labeled finite digraph with each path representing a chain of events as a linearization of an occurrence net segment of the Petri net; decomposing the labeled finite digraph derived from the CFSM into segments; and mapping each decomposed segment of the labeled finite digraph derived from the CFSM to respective MSCs for output of a compositional MSC based upon the mapped to MSCs.