When the safety argument only addresses what has changed

One strategy that a safety case can use to argue safety reduces the assurance evidence required, by justifying only the change from a previous system/service state, instead of justifying the safety performance of the complete service. However, use of this strategy may depend on it being permissible to apply risk acceptance principles like 'as safe as before' or GAMAB in the legal and regulatory framework applying to the service.

The Safety Case Report format allows for this strategy by including the necessary additional parts of the safety argument (e.g. those to establish the Internal Assurance Scope) required to be addressed under this strategy.