A Systems Viewpoint on the Integration of Subsystems Developed with Heterogeneous Safety Standards

Defence programmes are often characterized by a high level of complexity: in terms of the technical systems involved, their management and supply chain arrangements, and the dynamic nature of the risks involved. Existing safety standards like IEC 61508 provide a well-known framework for the functional safety of electrical, electronic, and programmable electronic safety-related systems, but do not address the complexity commonly found in such systems. In IEC 63187-1, the International Electrotechnical Commission is drafting a new standard to provide a safety framework using modern systems engineering principles that build on ISO/IEC/IEEE 15288, and extending it with requirements to make it appropriate for critical systems in the defence sector. This paper discusses how IEC 63187-1 deals with the heterogeneity of safety realisation standards using two major concepts that are Measures of Importance and Design Criteria.