Manning Analysis in Naval Ship Concept Design

Abstract

The total cost of ownership of a naval ship is largely influenced by decisions made during concept design. In recent years the US Navy has undertaken numerous initiatives to reduce total ownership cost. This has prompted particular interest in reducing manning, as this is the largest single expenditure in total ownership cost. Normally ships are designed and then a study is performed to determine their required manning, but manning has a significant design impact and designs can either be too small to accommodate necessary manning or too large and costly if manning is overestimated. Manpower analysis implemented early in the design process and included in design synthesis could significantly minimize total ownership cost while optimizing ship design performance. The Department of Aerospace and Ocean Engineering at Virginia Tech has developed a Multi-Objective Genetic Optimization process to aid in ship concept exploration. This thesis describes a manning model created to be incorporated into this ship synthesis and optimization. DDG-51 guided missile destroyer manning is used as a baseline for a guided missile destroyer (DDGx) concept exploration. ISMAT (Integrated Simulation Manning Analysis Tool) discrete event manning tool is used to decompose complex ship operations into functions and tasks to build scenarios and assign crewmembers to accomplish maintenance and ship operations and ultimately calculate manning requirements as a function of ship mission, system, size, automation and maintenance strategy. The manning model results are then linked to the ship synthesis model and design optimization to determine an estimated crew number for a particular ship design. This thesis demonstrates that a manning estimation tool can effectively be linked to a naval ship concept exploration process and have a significant impact on selected designs.