improve decision support for system of systems problems. Specifically, an effective system of systems engineering framework is needed to help decision makers to determine whether related infrastructure, policy and/or technology considerations as an interrelated whole are good, bad or neutral over time. The need to solve system of systems problems is urgent not only because of the growing complexity of today's challenges, but also because such problems require large monetary and resource investments with multi-generational consequences. System-of-systems topics The system-of-systems approach While the individual systems constituting a system of systems can be very different and operate independently, their interactions typically expose and deliver important emergent properties. These emergent patterns have an evolving nature that stakeholders must recognize, analyze and understand. The system of systems approach does not advocate particular tools, methods or practices; instead, it promotes a new way of thinking for solving grand challenges where the interactions of technology, policy, and economics are the primary drivers. System of systems study is related to the general study of designing, complexity and systems engineering, but also brings to the fore the additional challenge of design. Systems of systems typically exhibit the behaviors of complex systems, but not all complex problems fall in the realm of systems of systems. Inherent to system of systems problems are several combinations of traits, not all of which are exhibited by every such problem: Operational Independence of Elements Managerial Independence of Elements Evolutionary Development Emergent Behavior Geographical Distribution of Elements Interdisciplinary Study Heterogeneity of Systems Networks of Systems The first five traits are known as Maier's criteria for identifying system of systems challenges. The remaining three traits have been proposed from the study of mathematical implications of modeling and analyzing system of systems challenges by Dr. Daniel DeLaurentis and his co-researchers at Purdue University. Research Current research into effective approaches to system of systems problems includes: Establishment of an effective frame of reference Crafting of a unifying lexicon Developing effective methodologies to visualize and communicate complex systems Distributed resource management Study of designing architecture Interoperability Data distribution policies: policy definition, design guidance and verification Formal modelling language with integrated tools platform Study of various modeling, simulation and analysis techniques network theory agent based modeling general systems theory probabilistic robust design (including uncertainty modeling/management) object-oriented simulation and programming multi-objective optimization Study of various numerical and visual tools for capturing the interaction of system requirements, concepts and technologies