To a System of Any Magnitude

What does the city traffic light system in Melbourne, Australia , have in common with the U.S. Missile Defense Agency’s Ballistic Missile Defense System (BMDS)? The answer is size and complexity.

When Melbourne’s traffic system was modeled with Raptor in the 1990s, it was one of the largest reliability block diagram models ever built. Even then, with a much earlier version of Raptor, the model size that could be constructed within Raptor was limited only by a user's computer memory.

Since then, we’ve made incredible improvements to Raptor, such as the addition of our Hierarchy object, which allows greatly simplified modeling of subsystems. Multiple components can be represented as a single object or expanded to a greater level of detail, and multiple RBD models can be linked together or embedded within one another.

These hierarchies are used extensively for BMDS, a system responsible for defending America and her allies from rogue conventional or nuclear missile launches. This is a system of systems, composed of ground-based radars, satellites, ships, missile interceptors, and a worldwide communications network that integrates all of it into one massive coherent entity. The BMDS model is composed of thousands and thousands of elements with incredible complexity and redundant paths that cannot be modeled with any other tool.

But beyond that, the elements of BMDS that participate in a mission vary from one engagement scenario to the next. An element that might be critical for one mission may not be needed at all for another. Calculating reliability, cost, and logistics parameters for such a fluid system will very quickly break the back of equation-based analysis tools. Raptor easily handles these changes with its ability to designate mission and nonmission time and its phasing features that allow the modeler to turn off or stress components at different levels depending on varying phases of operation.

It is capabilities such as these that attracted the Missile Defense Agency to trust the reliability assessment of one of the most important defense systems in history to Raptor.