Property decomposition to speed up analysis

The complexity and criticity of many real time systems suggest that the temporal reachability analysis technique can find a role in the industrial development of such systems. Unfortunately, the costs of time reachability analysis inhibits the systematic application of this kind of analysis in the early stages of development, when long verification sessions slow down the development process. Moreover, the large reachability space built for proving temporal properties reduces the size of specification for which temporal reachability analysis can be applied. We show how some easily accessible information about the system to be developed and the required properties can largely reduce in many interesting cases the size of the reachability space to be explored. In this way temporal reachability analysis can be used for verifying fairly large specifications and can be applied at the early stages of development without excessively slowing down the development process. In this last case, the time spent for verification at the early stages of development is paid back by the time later saved for correcting errors otherwise uncaught.