Abstract :
The rail sector is operating within a complex business environment. System suppliers are operating globally and railway authorities are seeking to procure systems from this worldwide supplier base. The complexity of these systems is increasing as rail authorities are required to ensure the interoperability of their systems with the systems of other railway authorities, for some designated routes, as well as interoperability with existing systems owned and operated by the authority. At the same time as this functional complexity of systems is increasing, the technical complexity of systems is also increasing as rail authorities seek to make operational and maintenance savings through the implementation of leading-edge technology. Amidst this increasing complexity, rail authorities need to be able to demonstrate to regulators that they are able to use such complex systems safely. To do this, rail authorities need to be able to show that they have considered the various ways in which the systems could cause accidents and mitigated these risks effectively and also that they have in place, ways of working that directly support the continued safe use of such systems. The author looks behind the “necessary evil” view of independent safety assessment to identify why, in his opinion, independent safety assessment is now essential for safety systems and how, by working together, those barriers that stand in the way of effective independent safety assessment can be eliminated
