Model Checking in Bits and Pieces

The central thesis explored in this paper is that parallel model checking is easily achieved through compositional methods. This may strike the reader as being self-evident. Nevertheless, it does not appear to have been considered before. The justification comes from the following observations: (1) the efficacy of a parallel program is inversely proportional to the amount of synchronization and communication across processors, and (2) compositional methods break up the analysis into nearly-independent parts; in each part, a program component is analyzed with limited knowledge of the internal state of other components. For loosely coupled programs, therefore, one may expect compositional methods to work well, and to further benefit from parallelization.