Track 1 Session 10
9:10 to 10:10 a.m. Friday June 22, 2007

Determining the Ballistic Missile Defense Shields Effective Reliability

The Ballistic Missile Defense System (BMDS) is a phased arrangement of equipment that is designed to engage a limited number of ballistic missiles launched against the United States and her allies. A phased system is one that changes its characteristics or topology over time. Determining the reliability of phased systems requires the rather complex aggregation of results across phases. For any realistic equipment architecture, simulation is the only technique with the capability to resolve the reliability of a phased system. The mission reliability parameter is often determined for a complex phased system but effective reliability can often be a better measure of system performance. The mission reliability parameter accounts for the suitability aspects such as hardware and software failures during a phased mission, while the effective reliability parameter simultaneously accounts for both suitability and effectiveness issues that are statistically dependent. Using realistic but non-classified data, we will demonstrate that the BMDS community's current reliance on the mission reliability parameter will overestimate the abilities of the system while the effective reliability parameter will yield a better estimator of the systems true potential to negate ballistic missiles.

Key Words: Ballistic Missile Defense, Effective Reliability, Mission Reliability, Phasing, Reliability Block Diagrams, Simulation