a) This Defence Standard defines requirements to be met to support the demonstration that safety risks arising from materiel failure in submarines are ALARP throughout the CADMID cycle in accordance with Def Stan 00-56, and that sufficient objective evidence is available to assure Duty Holders and Regulatory Authorities of that.

b) The output arising from this Standard shall be consistent with the requirements of JSP 430 and JSP 518, and with the submarine class safety case, and shall form an intrinsic part of the certification to operate.

c) This Standard defines the MoD policy for specifying the minimum Quality and Quality Assurance required for Safety in Submarines through the implementation of Submarine Operating Centre policies and standards.

d) This Standard is developed from the Principles specified in MAP 01-126, Tolerability of Risk for Submarines (TOR(SM)) as relating to Safety Categorisation and Classification. The design philosophy underpinning TOR(SM) is based on the Defence in Depth (DiD) approach to ensuring the safety of the submarine. The requirements and guidance in this Standard therefore support this approach but also address instances where safety is maintained through a single line of defence.

e) The Standard comprises two Parts:

1) Part 1 is mandatory, setting out the key requirements including the safety principles, definitions and high-level methodology required to Categorise functions and Classify systems, structures and components.

2) Part 2, this Part, sets mandatory QA requirements in the main text. It also contains guidance in its Annexes on grading Quality Assurance requirements. Part 2 indicates the minimum Quality Assurance level required to support a demonstration that the safety risks are appropriately managed.