Manning and Automation Model for Naval Ship Analysis and Optimization
Scofield, Tyson James
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The manning of a ship is a major driver of life cycle cost. The U.S. Government Accounting Office (GAO) has determined that manpower is the single most influential component in the life cycle cost of a ship. Life cycle cost is largely determined by decisions made during concept design. Consequently, reliable manpower estimates need to be included early in the design process, preferably in concept design. The ship concept exploration process developed at Virginia Tech uses a Multi-Objective Genetic Optimization to search the design space for feasible and non-dominated ship concepts based on cost, risk and effectiveness. This requires assessment of thousands of designs without human intervention. The total ship design problem must be set up before actually running the optimization. If manning is to be included in this process, manning estimate tools must be run seamlessly as part of the overall ship synthesis and optimization. This thesis provides a method of implementing a manning task network analysis tool (ISMAT, Integrated Simulation Manning Analysis Tool, Micro Analysis and Design) in an overall ship synthesis program and design optimization. The inputs to the analysis are ship systems (propulsion, combat systems, communication, etc), maintenance strategy, and level of automation. The output of the manning model is the number of crew required to accomplish a given mission for a particular selection of systems, maintenance and automation. Task network analysis programs are ideal for this problem. They can manage the probabilistic nature of a military mission and equipment maintenance, and can be used to simplify the problem by breaking down the complex functions and tasks of a shipâ s crew. The program builds large and complex functions from small related tasks. This simplifies the calculation of personnel and time utilization, and allows a more flexible scheme for building complex mission scenarios. In this thesis, ISMAT is run in a pre-optimization step to build a response surface model (RSM) for calculating required manning as a function of systems, maintenance and automation. The RSM is added to the ship synthesis model to calculate required manning, and a concept exploration case study is performed for an Air Superiority Cruiser (CGX) using this model. The performance of the manning model in this case study is assessed and recommendations are made for future work. This research shows that there is a difference between minimum manning and optimal manning on US Navy Ships.
- Masters Theses