Deriving Safety Requirement Hierarchies for Families of Maritime Systems

Abstract

Ensuring the safety of advanced maritime vessels is a challenging task. While technological developments provide new options for their design and operation, the criteria for certification, such as class rules intended to ensure safety, may not be flexible enough to accommodate rapid changes. Innovation may enable more efficient, greener, and smarter systems but it may also introduce new hazards that are not addressed by current safety requirements. This paper proposes a method aimed at developing requirement hierarchies that are generic for a family of systems (such as a class of ships) and that can be adapted and specialised for a subset of the family or a particular system. Systems-theoretic process analysis (STPA) is used to develop safety requirements that are structured in a way that ensures that they can easily be kept up to date to accommodate new technological solutions and new alternatives for the design and operation of maritime vessels.