The process concerning the removal of this obstruction involves catheterisation. It then obstructs the cerebral artery due to its smaller cross section. In the cerebral arteries, this occlusion can take place due to the presence of a clot that has formed at another location of greater diameter. Thrombosis is produced by the formation of a clot inside blood vessels causing an abrupt interruption of the blood flow. (2005, 2008) for an in-depth description of distributed simulation using EcosimPro). For very complex systems, the simulation may be distributed on several computers (see Alves et al. (2008) for an in-depth description of the methodology of object-oriented environments. See Urqu´ıa and Dormido (2003) and Mart´ın-Villalba et al. Finally, the integration of the mathematical system is solved using advanced numerical solvers, such as the Fortran meth- ods DASSL, DASSLX, DASPG and DASPK. Depending on the system, it may be necessary to break algebraic loops or solve high index problems. EcosimPro has symbolic methods, which manip- ulates the mathematical system and looks for the optimal path and steps, which should be followed to solve the system. The global mathematical system, which is formed by the interconnection of the individual models, should be solved as a whole. The user builds his/her own model by connecting to each other these components. The mathematical modelling is represented by DAE (implicit or ex- plicit) and discrete events, and then encapsulated in reusable com- ponents.