 
Summary: Model Checking of Message Sequence Charts
Rajeev Alur ? and Mihalis Yannakakis ??
Abstract. Scenariobased specifications such as message sequence charts
(MSC) offer an intuitive and visual way of describing design require
ments. Such specifications focus on message exchanges among communi
cating entities in distributed software systems. Structured specifications
such as MSCgraphs and Hierarchical MSCgraphs (HMSC) allow con
venient expression of multiple scenarios, and can be viewed as an early
model of the system. In this paper, we present a comprehensive study of
the problem of verifying whether this model satisfies a temporal require
ment given by an automaton, by developing algorithms for the different
cases along with matching lower bounds.
When the model is given as an MSC, model checking can be done by
constructing a suitable automaton for the linearizations of the partial
order specified by the MSC, and the problem is coNPcomplete. When
the model is given by an MSCgraph, we consider two possible semantics
depending on the synchronous or asynchronous interpretation of concate
nating two MSCs. For synchronous model checking of MSCgraphs and
HMSCs, we present algorithms whose time complexity is proportional
to the product of the size of the description and the cost of processing
