Percolation theory provides models for a wide variety of natural phenomena. One of these phenomena is the dielectric breakdown of composite materials. This paper describes how we implemented the percolation model for dielectric breakdown in a massively parallel processing environment. To achieve this we modified the breadth-first search algorithm such that it works in probabilistic process networks. Formal methods were used to reason about this algorithm. Furthermore, this algorithm provides the basis for a JCSP implementation which models dielectric breakdowns in composite materials. The implementation model shows that it is possible to apply formal methods in probabilistic processing environments.