InterAction has specialist knowledge of safety case development, gained through numerous projects in the defence sector. We write safety cases in accordance with governing standards, usually Def Stan 00-56 or JSP454, taking account of the safety criteria in the contract and the higher level safety criteria appearing in JSP454 and national/international legislation. Depending on the contract, we employ some or all of the following techniques:

• Human error identification, including HEART, THERP, SHERPA and QHRA



• Human error quantification through expert group consensus and by reference to error rate databases



• Quantification of failure probabilities through close working relationships with designers during safety case development



• Error and failure modelling with fault tree and event tree analyses



• Safety case formats as defined in military standards (Def Stan 00-56 and JSP454)

InterAction has developed a diverse portfolio of safety cases in the civil and defence sectors. Most large projects in both arenas require a full safety case, including human reliability analysis (HRA) and hardware reliability analysis. Ideally, the safety case commences early in the design process and continues through to production and beyond. 

HRAs are usually commissioned for large, complex systems such as nuclear power stations or submarines, but increasingly they are a requirement for smaller projects. 

Irrespective of the size of the system, the presence of human operators introduces the potential for human error. Good safety case management at the concept, design and production stages, as well as in operation, can reduce this potential to acceptable limits.

Our in-house software programme, InterRISK, gives us the capability to manage safety cases comprehensively and to customer-specified formats, and to provide accompanying electronic hazard logs with our reports when required.

You can find more about our work in the safety area from our capability statements, accessible from the homepage.