Abstract: An asynchronous parallel simulation protocol useful to simulate events in a stream processing platform. The invention is a windowing scheme which is suitable for distributed stream computing platforms containing facilities for supporting fully asynchronous processing elements and downstream event flows. It is a realization of the concept of a BSP superstep based oracle simulator that enables using statistics from the recent past to conduct the actual optimistic simulation at low rate of straggler messages. The invention is capable of achieving good statistic agreement with results from sequential simulations of the same models.