Assessing complex failure scenarios of on-board distributed systems using a Markov chain

Abstract

Vulnerability reduction is an important topic during the design of naval ships because they are designed to operate in hostile environments and because their on-board distributed systems are becoming increasingly complex. The vulnerability needs to be addressed in the early design stages already, in order to prevent expensive or time-consuming modifications in later, more detailed design stages. However, most existing methods for assessing the vulnerability are better suited for more detailed design stages. Furthermore, existing methods often rely on pre-defined damage scenarios, while damage -or system failure in general -may also occur in ways that were not expected beforehand. This paper proposes a method that addresses these gaps. This is done by incorporating several additions to an existing vulnerability method that has been developed by the authors, using a Markov chain. With this method, there is no longer a need for modelling individual hits or failure scenarios. The additions are illustrated by two test cases. In the first one, a notional Ocean-going Patrol Vessel is considered, and damage is related to physical locations in the ship. The second test case considers a chilled water distribution system in more detail, with failures modelled independent from the physical architecture. The quantitative nature of the results provide an indication of the generic, overall vulnerability of the distributed systems, which is meant to be used in the early design stages for identifying trade-offs and prioritising capabilities.

Naval Engineering and Ship Control Special Edition Editorial

“…However, the increasingly complex nature of these vessels and their dependancy on distributed systems, such as power systems, cooling systems and information technology systems, impedes vulnerability analysis in the early design stage (Goodrum et al 2017;de Vos and Stapersma 2018). A novel method to assess vulnerability reduction at the early ship design stage, using a Markov model is presented in Habben Jansen et al (2019). This method allows to account for complex damage scenarios by generalising damage scenarios and thus prevents the need for simulation of a large number of individual hit scenarios at the early design phase.…”

“…• The survivability of naval platforms and in particular design vulnerabilities (Habben Jansen et al 2019); • The growing role of pulsed-power and energy storage systems and their control (Rashkin et al 2019;Edrington et al 2019); • The growing tension between reducing ships environmental impact and maintaining manoeuvring performance and safety (Theotokatos et al 2019;Eriksson and Llamas 2019); and • The transition toward reduced crews and autonomous shipping, while maintaining safety of operations (Zaccone and Martelli 2019; Bibuli et al 2019).…”

No free lunch for avoiding clustering vulnerabilities in distributed systems

“…Distanceminimization drivers can be economic, e.g., minimizing material cost 28,29 , or physical, e.g., minimizing energy loss or latency 7,[30][31][32] , or a combination of economic and physical 33,34 . Regardless of the driver, connection-distance minimizing arrangements of design elements induce spatial grouping, and that grouping produces clustering vulnerabilities 35,36 .…”