Gunion (to be published

A critical issue for complex component-based systems design is the modeling and anal-ysis of architecture. One of the complicating factors in developing architectural models is accounting for systems whose architecture changes dynamically (during run time). This is because dynamic changes to architectural structure may interact in subtle ways with on-go-ing computations of the system. In this paper we argue that it is possible and valuable to provide a modeling approach that accounts for the interactions between architectural reconfiguration and non-reconfigura-tion system functionality, while maintaining a separation of concerns between these two as-pects of a system. The key to the approach is to use a uniform notation and semantic base for both reconfiguration and steady-state behavior, while at the same time providing syntac-tic separation between the two. As we will show, this permits us to view the architecture in terms of a set of possible architectural snapshots, each with its own steady-state behavior. Transitions between these snapshots are accounted for by special reconfiguration-triggering events.