Railroad system is consisted of resources of rail track, signal system, and vehicles. Railway operation must use these limited resources and maximize resource utilization. Line capacity(number of trains throughput/day) is determined by such as parameters, line utilization rate($alpha$), dummy rate for the break-through hour($eta$), and dummy rate for the number of rail track intervals($delta$). Line capacity simulation(LCS) determined the line capacity through simulation given $alpha$, $eta$, and $delta$. This paper deals with the development of parameter evaluation simulation(PES). PES presents the decision maker with the relationship of line capacity and measurement of robustness for various scenarios in different parameters and then the decision maker can determine the appropriate parameters.