Naval ships need to be able to conduct missions in a variety of circumstances. This includes the ability to fulfil specific tasks in a damaged state. Vulnerability reduction measures are taken during the early stage distributed ship system design process, to ensure the availability of the required systems in damaged state. Traditionally these vulnerability reduction measures are based on design rules or best practices resulting from past experiences. Therefore the measures are not per definition applicable for future warships, as both the system concepts and operational environment changes. Recently developed vulnerability assessment methods are able to determine the vulnerability of a design early in the design process. With integration of these methods in the early stage design process, the results of the analysis can be used to generate less vulnerable distributed ship system designs. This thesis proposes an integral and holistic approach of optimization of the design variables and distributed networks as these are becoming increasingly interdependent. The result of this approach is a model which generates distributed ship system designs consisting of component positions, a topology and routed connections based on a pre-defined system configuration and constraining physical architecture. Five testcases were conducted using this model, showing the necessity of the integral and holistic approach as the extent to which the contemporary design rules are implemented depends on the network complexity and operational environment. The developed method assists the naval architect in generating designs and requirement elucidation in the concept exploration stage. ... Read more

All ships rely on many on board systems to reliably complete their missions (e.g. transporting containers, laying pipes or protecting the seas). However, for many of these ships, the detailed design of these systems is put off until the later stages of the design. For most ships, this will create no problems. However, for those complex vessels for which the system design dictates and drives the size and performance of the vessel, changes in a later design stage can be difficult and costly. For these complex ships (e.g. naval ships, pipe-laying vessels, etc), more focus should be spent on system design earlier in the ship design process.

A important aspect of the system design is determining and designing the system topology (e.g. how components within a distributed system are connected). To achieve this, the ongoing PhD research of de Vos [2017] created the "Ship Distributed Systems Automatic Topology Generator" (SDS-ATG) tool. This tool combines the fundamentals of network theory and marine engineering to automatically generate a multitude of ship distributed system topology concepts. A genetic algorithm is then used to optimize these topologies with respect to system performance and cost. The performance objective can be related to the vulnerability (or robustness) of the found system topologies.

This MSc thesis focusses on the investigation and development of a vulnerability assessment method, based on network theory, that can be used to assess the generated ship distributed system topologies. The assessment method will be used to better define the performance of a system design, based on the vulnerability of system topologies in early stage design.

To create the method proposed within this thesis, it is necessary to evaluate the created SDS-ATG tool, as well as vulnerability prediction methods and metrics available from literature (and used in other fields). Next, the newly developed vulnerability assessment method is discussed. This discussion is based on the assumptions made to define the method, the steps taken within the method, and the advantages and disadvantages of the method. Finally, the new vulnerability assessment method is verified using hand calculations, and the results of a practical system design test-case are used to show the improvements that can be made with regards to the vulnerability of the system topology design.

To conclude, the developed vulnerability assessment method is seen to greatly increase the capability of the SDS-ATG tool as an eraly stage design tool.
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