Survey on formal methods and tools in railways: the ASTRail approach

Formal methods and tools have been widely applied to the development of railway systems during the last decades. However, no universally accepted formal framework has emerged, and railway companies wishing to introduce formal methods have little guidance for the selection of the most appropriate methods and tools to adopt. A work package (WP) of the European project ASTRail, funded under the Shift2Rail initiative, addresses this problem, by performing a survey that considers scientific literature, international projects, and practitioners' perspectives to identify a collection of formal methods and tools to be applied in railways. This paper summarises the current results of this WP. We surveyed 114 scientific publications, 44 practitioners, and 8 projects to come to a shortlist of 14 methods considered suitable for system modelling and verification in railways. The methods and tools were reviewed according to a set of functional, language-related, and quality features. The current paper extends the body of knowledge with a set of publicly available documents that can be leveraged by companies for guidance on formal methods selection in railway system development.