Simulation is a mean for verifying the quality of an architectural specification. Some approaches have been proposed in the past. Each approach has its own internalsimulation engine, and allows for certain types of simulations.Goal of this paper is to propose SASIM, a softwarearchitecture-level simulation technique for modelingand simulating architectural specifications. It improves existing techniques, by permitting various kinds of simulation, and making use of SPIN as external simulator. This allows a real and useful integration between simulation and exhaustive verification. The paper discusses SASIM and compares it with existing techniques.