In this study, we describe a decision process for establishing the threshold reliabilities for components of naval major caliber ammunition. A measure of reliability performance is described which relates directly to the weapons system's performance in a naval gunfire support environment. We use a simulation model to establish this relationship, a regression metamodel to estimate its parameters, and a simple decision process to specify component reliability thresholds which ensure that the ammunition is mission effective. We present this paper as an example of the integration of discrete event dynamic system analysis within a decision process.