An improved approach for on-board distribution system robustness estimation in early-stage ship design

Reliability and survivability play a key role in the ship operation and ship design process of navy ships, but increasingly also of complex commercial vessels. These requirements prove relevant for different elements within the ship design scope, including the distribution system design of data, energy and fluid (water, fuel, oil, etc.). In early-stage ship design, distribution system robustness estimation is crucial in performing a substantiated trade-off between system availability and system investment costs. Van Mieghem et al. have developed a framework for computing topological network robustness; a generally applicable robustness approach using a graph representation as network system model. This framework has been applied on on-land power grids and more abstract networks such as the internet. However, due to the general nature of the framework, the applicability of the framework to on-board distribution systems is not self-evident. In this study, the required assumptions and adjustments to applyt his mathematical approach to on-board distribution systems are described. Moreover, the usefulness of this method for system robustness estimation in early-stage ship design is considered and demonstrated. In conclusion, an improved robustness estimation of distribution systems makes for an overall more reliable ship; a property to be pursued for increasingly complex ships.