Section 3 System Context of the NS Software Rules

3.1 General

The NS Software Rules are designed to ensure that designers properly specify the Relevant Hazard Requirements for, and the level of reliance that is placed on, any Software. This is to be defined at the Engineering System level using a risk-based approach. Figure 1.3.1 NS Software Rules Overview Process Diagram shows an overview of the main activities that must be undertaken in order to provide assurance of Engineering Systems implemented with Software, and the parties responsible for undertaking these activities. Figure 1.3.1 NS Software Rules Overview Process Diagram shows that Relevant Hazard identification and the definition of Relevant Hazard Requirements to remove or control the Relevant Hazards are initially system and Engineering System level activities which are outside of the scope of the NS Software Rules. When additional Relevant Hazards are identified that cannot be removed at an Engineering System Level or a System Level, the Producer of Software is then involved in specifying the Relevant Hazard Requirement.

Figure 1.3.1 NS Software Rules Overview Process Diagram

The NS Software Rules recognise that delivered Engineering Systems are often tailored versions of existing systems, or are constructed from existing or modified subsystems. In these circumstances, it is permissible for existing evidence of compliance to the NS Software Rules to be reused or to form the basis of a new submission for Classification. For example, it would be acceptable for an existing hazard and risk assessment to be reviewed and revised for a new ship in order to derive an updated set of Relevant Hazard Requirements for the new context of use.