Composable simulations

While there has been much attention paid to the applications of modeling and simulation (M&S) by the Department of Defense (DoD) lately, little has been done to address those broad technology areas that enable application-oriented simulations to be more easily constructed, run and analyzed. Model composabilty is the ability to compose models/modules across a variety of application domains, levels of resolution and time scales. A composability framework for simulations offers a quantum leap in capability and provides the sought after ease of use. However, composability is still a frontier subject in modeling and simulation, and current capability is limited. While model reuse is close to the Holy Grail of M&S, the goal is not within sight. We are discovering that unless models are designed to work together, they don't (at least not easily and cost effectively). Without a robust, theoretically grounded framework for design, we are consigned to repeat this problem for the foreseeable future. This paper outlines the challenges and basic research that needed for composable simulation developments.