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en-USwww.sname.org/sname/mt en-US en-US en-USJuly 2012 constituent parts. The photo on page 62 provides an example implementation of the virtual warship reference architecture. is implementation represents a modular environment that spans from a synthetic battlespace down to physics-level repre -sentation of systems and components on a ship. e Virtual Warship Federation is composed both of government o the shelf/ commercial o the shelf applications and models built using an NNS-developed M&S toolset called the common simulation framework (CSF). For NNS, the reference architecture is always evolving as systems grow in complexity and lessons learned from M&S projects are incorporated. The bottom line is that, to create the virtual carrier, decision makers at NNS had to think about the whole as the indi -vidual parts were developed. e primary lesson learned in development of the vir -tual carrier was that most commercial M&S tools that NNS used in the manufacturing world did not support the interoperability needed. As a result, NNS developed CSF, built completely with open architecture as its foundation. is enables it to integrate distributed simulation technologies such as HLA?s run time infrastructure at its core. Simulation developers have full access to the core components and libraries within the simulation engine. Reuse is enabled by developing external com -ponent libraries that can be used for a specic problem space or system model. Virtual carrier development In 2004, NNS and the navy formally created a government/industry team to develop the virtual carrier in support of the CVN 78 Ford class program. Of particular interest to the program was the requirement for the Ford class to be able to generate 25% more com -bat sorties than the CVN 68 Nimitz class. e virtual carrier M&S integrated product team (IPT) developed a functional decomposition of sortie generation rate (SGR) and mapped simulation components to the functions. e virtual carrier SGR model shown in the photo on page 63, incorporates vari -ous functions determined by the IPT to be modeled to assess SGR and required to be represented in the simulation. ese func -tions are represented in a ight deck model, ordnance handing model, and naval avia -tion maintenance and supply model and are coupled such that they run together as a federation. e virtual carrier SGR model has been undergoing iterative development since 2004 and uses an agile development practice based on Scrum with XP software engineering practices. The verification, validation, and accreditation process is continuous and accomplished as part of the requirements and testing process. e virtual carrier development process is governed by the requirements of the CVN 78 program to support development and opera -tional test events as described in the program?s test and evaluation master plan (TEMP). Being driven by the program?s TEMP makes for cost-eective, purpose-driven develop -ment and creates a long-term perspective for the application of M&S to support what the program determines to be high-value or risk areas. As design or system questions have arisen during the development of the ship, the virtual carrier IPT works those items into its iterative development cycle as needed for decision support timelines. Initially, the virtual carrier was set up to support design and development testing; however, PEO Carriers directed a study to determine an SGR methodology in support of initial operational test and evaluation. is study found that using the virtual car -rier M&S environment and development process could potentially save the pro -gram more than $200 million as opposed to physical testing alone. Development of a virtual test environment provides the abil -ity to address many dicult problems for ship operational testing. Research and development eorts have extended the virtual carrier capabilities to include decision support tools for operators in the loop. One such tool, Spot Sheet Lite, is used to collaboratively plan and train the eet on spotting of aircraft on the virtual carrier?s ight deck and in the hangar bay. e use of the virtual carrier, coupled with real-world physical testing, strikes an eec -tive balance to best assess the capability of the next generation aircraft carrier. MTRob Lisle, Bi ll Laz, and Robin P. Penley ar e employ -ees of Newport News Shipbuilding. For more on their backgrounds, see the Feature Contributors section on pages 5-6 of this issue. e virtual carrier has its roots in two DARPA programs, SBD and synthetic theater of war (STOW). Spot Sheet Lite decision support tool.