Investigating fulfilment of traceability requirements in a combined process for safety and security assessments.

Combined harm assessment of safety and security for information systems CHASSIS method defines a unified process for safety and security assessments. CHASSIS applies techniques from safety and security fields - e.g., misuse case and HAZOP - to identify and model hazards, threats, safety and security requirements to a system. Ensuring traceability between safety and security requirements as well as other artefacts is one of the important tasks required to provide safety and security assurance. In this paper, we present an approach for traceability, called SaTrAP, which was used to provide traceability support to CHASSIS. We discuss the application of SaTrAp and CHASSIS with the help of an ATM remote tower example. We evaluate whether CHASSIS together with SaTrAp fulfils the traceability requirements set by standards. In this regard, we have analysed regulations/standards from ATM domain for requirements on traceability. We also analysed how security has been addressed by these standards.