A two-day workshop was held on January 13–14, 2016, at the National Science Foundation in Arlington, Virginia, with the goal of defining directions for future research in modeling and simulation and its role in engineering complex systems. The workshop was sponsored by the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), the Air Force Office of Scientific Research (AFOSR), and the National Modeling and Simulation Coalition (NMSC) in conjunction with its parent organization the National Training and Simulation Association (NTSA). This book documents the findings emanating from this workshop.

The goal of the workshop was to identify and build consensus around critical research challenges in modeling and simulation related to the design of complex engineered systems—challenges whose solution will significantly impact and accelerate the solution of major problems facing society today. Although modeling and simulation has been an active area of study for some time, new developments such as the need to model systems of unprecedented scale and complexity, the well-documented deluge in data, and revolutionary changes in underlying computing platforms are creating major new opportunities and challenges in the modeling and simulation (M&S) field. The workshop focused on four main technical themes:(1) conceptual models,(2) computational issues,(3) model uncertainty, and (4) reuse of models and simulations. The workshop resulted in large part from an initiative led by the research and development committee of the National Modeling and Simulation Coalition (NMSC) aimed toward defining a common research agenda for the M&S research community. Recognizing that the modeling and simulation community is fragmented and scattered across many different disciplines, communities, and constituencies, there is a need to gather individuals from different communities to articulate important research problems in M&S. Presentations and panel sessions at several modeling and simulation conferences were held leading up to and following the January workshop to raise awareness of this activity. Detailed planning began in September 2015 with the formation of the workshop steering committee consisting of Richard Fujimoto (chair, Georgia Tech, and then