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With the advent of new technologies for electric ships, there is a need for a robust methodology to quantitatively evaluate their impact on the performance of a ship, while accounting for the uncertain nature of their parameters. To that end, this paper gives an overview of the Technology Identification, Evaluation, and Selection, or TIES, methodology as applied a 10kton surface combatant. This case study highlights the ability of TIES to aid in a broad exploration of the design space, by giving designers key tools that allow them to show in a traceable manner the tradeoffs involved in infusing technologies and making other design choices, as well as which designs best meet different sets of Figures of Merit. This ultimately allows decision-makers to determine what technologies or design choices to invest in to yield a ship with the performance parameters that will best serve the needs of its stakeholders.

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Modern naval missions rely increasingly on a complex array of electronic systems for a variety of functions including communications, sensing, weaponry, and countermeasures, greatly increasing the power requirements for future ships. To meet these needs, ships are transitioning to more electric architectures and require the infusion of new technologies. Since technology development resources are often limited, it is vital to intelligently choose the most promising designs to invest in. However, this type of decision-making is not necessarily straightforward. Firstly, the ship itself is a highly intricate system, with thousands of components and interactions that can be modeled at a variety of fidelity levels and time scales. Secondly, the final decision depends on the various objectives, sometimes conflicting, of each decision-maker involved in the process, making traceability and justification for the final selection a challenge. Therefore, there is a need for a design decision-support environment that brings together all the technical data about the performance aspects of various ship designs and technologies in a way that allows stakeholders to interact with the information in a more dynamic, traceable manner, in order to make more informed decisions. This paper is introducing an environment that is being created as part of a study with the Electric Ship Research and Development Consortium (ESRDC) on High-Temperature Superconducting (HTS) technologies sponsored by the U.S. Office of Naval Research (ONR) and presents some potential examples of how stakeholders could use it in the decision-making context. This environment is built upon the foundation of the Technology Identification, Evaluation, and Selection (TIES) methodology, originally formulated for aircraft design, now adapted for electric ships. TIES was developed to address the need for a design methodology that accounts for the uncertain nature of new technologies, integrating probabilistic analysis and other advanced design methods, as well as the multi-objective nature of modern design decision-making. The environment walks a user through the steps of the TIES methodology, starting from defining key objectives and metrics of interest and then moving to generation of a baseline and ship architecture alternatives via morphological analysis. Semi-automated modeling and simulation capabilities were then developed to enable the creation of a set of potential designs, allowing for a broader design space exploration than would be possible with traditional point-design-based processes, allowing the user to more clearly see the impact of lower-level ship parameters on system-level metrics of interest. Constraint and sensitivity analyses are then performed to gain a further understanding of the relationships and tradeoffs among the ship design variables, what regions of the design space are most promising, and what requirements most strongly impact the space of feasible designs. The environment then leverages the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) to allow users to dial in relative importance weightings of the system-level metrics of interest to determine which ship designs best meet their needs. Once several promising ship designs have been selected based on all the information shown in the environment, these options can be analyzed in more detail.

The Department of the Navy 2021 Unmanned Campaign Framework has identified a need for increased capability in long-term autonomous maritime systems. In the context of this research, long-term autonomy is defined as the capabilities of self-governance, situational awareness, and operation independent of human interaction over a prolonged period. DARPA’s Anti-Submarine Warfare Continuous Trail Unmanned Vessel (ACTUV) program, now the U.S. Navy’s Sea Hunter program, among others, showcases the Navy’s commitment to develop and explore unmanned autonomous maritime systems. One of the challenges for development of these unmanned systems lies in the ship design process.  Traditional ship design methods assume crewed operations when sizing the systems, generating layouts, and considering operational requirements.  Existing unmanned maritime systems are often retrofitted to be unmanned rather than being uniquely designed for their purpose. Even in cases where autonomous systems are designed from scratch, these systems are fundamentally limited by technologies developed for traditional vessels. This can result in suboptimal solutions and missed opportunities. In particular, a lack of focus on reliability and endurance in both technology development and early in the design process results in significant impacts to unmanned systems. Reliability is often measured using mean time between failures. Given that maintenance is traditionally carried out frequently, reliability is not often a limiter for mission success, as the crew can handle non-critical failures. This assumption becomes invalid in the sphere of autonomous ship design, where theater maintenance is not feasible. For example, in a test voyage from SanDiego to PearlHarbor, Sea Hunter relied on crew on a support vessel to resolve several mechanical issues which arose in its journey. This suggests a possible technology gap in the reliability of subsystems key to autonomous maritime systems. Entwined with reliability is endurance. Endurance refers to how long the vessel can stay out at sea, a critical factor for many autonomous missions. Additional aspects of traditional ship design will need to be altered, including but not limited to the following: human support systems, human interfaces, and general structural design.The authors propose a set of modifications to the traditional ship design process to support the design of autonomous ships starting from concept design through full contract design.  Design disciplines specifically tailored to unmanned system design will be incorporated into the design process.  A technology impact forecasting (TIF) study will be conducted to determine key areas of research needed to support future unmanned systems.  This approach results in system performance metrics needed to meet requirements and quantifies the deficits or surpluses by comparison to a baseline vehicle and mission. The baseline mission for this analysis will be a security anti-submarine warfare activity similar to the ACTUV program, with an initial endurance goal of 90days. The TIF analysis of this baseline mission will quantify gaps in performance metrics and will offer a guideline for where further research and investment are required to enable the vision of long-term autonomous maritime systems.