 sample environment) can multiply neutron trajectories by splitting the neutrons into several possible final states and assigning the appropriate probability to each of them, thus keeping the total neutron intensity either constant or decreasing if neutrons are lost.Instrument parts are represented by modules which run independently in a pipe structure during simulation.Neutrons are passed from one module to the next in packages of typically 10000 neutrons, meaning that for most simulations that require more statistics, all modules run in parallel.