Exploration of System Vulnerability in Naval Ship Concept Design

This paper presents a methodology and analysis tool to explore naval ship system vulnerability using a simplified preliminary arrangement and vulnerability (Pa&V) modeling approach in the concept and requirements exploration (C&RE) process at Virginia Tech. This C&RE process uses a multiobjective genetic optimization (MOGO) to explore the design space for nondominated ship design solutions based on design effectiveness, cost, and risk. The previous C&rE process evaluated ship characteristics and only intact system options to determine a design overall measure of effectiveness (OMOE) through the calculation of Measures of Performance (MOPs). Vulnerability is very dependent on system design, architecture, and spatial arrangement, and for simplicity these were not developed or calculated. The new C&RE uses a simplified Pa&V model so that an Overall Measure of Vulnerability (OMOV) can be calculated for each ship design using the new process and tools described in this paper. The OMOV is calculated by combining Vulnerability measure of performance scores across multiple ship mission options. It is then combined with the intact MOPs to calculate a more complete warfighting OMOE which can be used in the C&RE. 1. Introduction Typically, survivability analysis for naval ships is deferred until preliminary design or later. Many important design decisions regarding systems and system architecture are made in concept exploration and are difficult and costly to reverse. survivability is an important factor in assessing mission effectiveness, which is an important objective attribute in concept exploration and must be considered in these early decisions. However, several questions are raised when attempting to assess and consider survivability early:Is sufficient model detail and fidelity available during concept exploration to make a reasonable survivability assessment?If sufficient detail is available, does early survivability consideration impact the resulting design decisions?Are simplified, but traditional vulnerability models able to discriminate correctly between alternative designs, answer the right questions, provide important insight, and enable good decisions for moving forward into concept development and preliminary design?Are tools and resources available to consider survivability early or do we need a completely new approach and new tools?