The argument pattern relating to this stage is shown in Figure 21 and key elements from the pattern are described in the following sections.
This claim, which is made for each tier of the AS development, demonstrates that the safety requirements that were defined at the previous tier have been adequately allocated, decomposed and interpreted through the safety requirements that have been defined at the current tier.
It must be shown that the safety requirements at the current tier are sufficient to capture the intent of the inherited safety requirements. The definition of safety requirements must take account of the context of the design that is in place for this tier ([W]). To ensure that all the safety requirements from the previous tier are considered, the argument explicitly considers each of those safety requirements in turn though the creation of a claim (G4.3) for each requirement.
A claim is made for each of the safety requirements from the previous tier, demonstrating that one or more of the safety requirements defined at the current tier adequately capture the intent of that requirement. This is demonstrated using the evidence documented in the SR justification report ([R]).