A Markov-based vulnerability assessment of distributed ship systems in the early design stage

Abstract

Naval ships are designed to operate in hostile environments. As such, vulnerability reduction is an important aspect that needs to be assessed during the design. With the increased interest in electrification and automation on board naval ships, the vulnerability of distributed systems has become a major topic of interest. However, assessing this is not trivial, especially in early stage design, where the level of detail is limited, but consequences of design decisions are large. As such, a new method for assessing the vulnerability of distributed systems in early stage design has been developed. This method not only evaluates the vulnerability of a pre-defined ship concept, but also provides direction for finding other, potentially better concept. This is done from the perspective of operational capabilities. The method helps ship designers and naval staff in setting vulnerability requirements, developing new concepts, and identifying trade-offs in operational capabilities. The method uses a discrete Markov chain and the eigenvalues of the associated transition matrix. A test case considering vulnerability of a notional Ocean-going Patrol Vessel (OPV) with two different powering concepts illustrates the method. Furthermore, the new method is discussed in terms of design knowledge, including a comparison with other early stage vulnerability reduction methods. In addition to that, an improvement of an existing early stage design procedure for distributed ship systems is made, which shows how the various methods, including the new method, are envisioned to be applied in practice.