The evacuation time of a building in an emergency can be broken down into a number of constituent times including the pre-evacuation time and the travel time. This paper examines how distributions of pre-evacuation times affect the occupant travel time and hence their effect on the evacuation time in the Simulex model. A simple scenario is assessed mathematically and compared with the results from Simulex with further simulations carried out on a somewhat more complex scenario. Where we expect the pre-evacuation time to be characterised by a distribution of values simply adding the maximum pre-evacuation time and the movement time over-estimates the evacuation time. Furthermore, when the preevacuation distribution is small the travelling and queuing effects dominate the simulated evacuation time. When the pre-evacuation distribution is large then travel and queuing effects are not so important and it is the pre-evacuation time that dominates. Finally the paper examines some aspects of the Simulex model in situations where there is a high occupant density in a space.