Section 3 Software integrity and integration
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Submarine Assurance Framework, July 2022 - Volume 1 Submarine Assurance - Part 4 Whole Boat Requirements - Chapter 3 Requirements for Systems - Section 3 Software integrity and integration

Section 3 Software integrity and integration

Parent topic: Chapter 3 Requirements for Systems

3.1 Functional objectives

3.1.1 For any activity that relies on the integrated use of equipment or sub-systems that includes software, the risks associated with software and its integration into the equipment or sub-system shall be properly managed to ensure that for normal, abnormal and emergency operating conditions, a failure or unspecified behaviour of the software shall not result in:

  1. An event that escalates to a hazard;
  2. Impairment of the mitigation of a hazard; and
  3. Impairment of recovery from a hazard.

3.2 Performance requirements

3.2.1 Software is to be designed and tested in accordance with recognised standards.

3.2.2 The ways in which software could be a stimulus event to a hazard, impair the mitigation of a hazard, or impair recovery following such a hazardous event shall be communicated to the appropriate parties.

3.2.3 The production of software shall be managed so that the safety risks arising from the software production are reduced to an acceptable level.

3.2.4 Provision shall be made to protect systems against:

  1. Unauthorised installation, change or deletion of software or associated data;
  2. The installation or use of unauthorised software (e.g. running games or office applications); and
  3. Modification of the software function by additional or modified physical devices.

3.2.5 A system safety justification shall be developed to include the risks posed by the use of software and how those risks are reduced to an acceptable level.

3.2.6 The configuration status of the software on each submarine shall be captured and recorded, and the record maintained up-to-date for the life of the submarine.

3.2.7 The development and testing of changes to the software and data, including specific arrangements for onboard testing, shall be managed so that safety of the system, sub-system or equipment is not compromised.

3.2.8 The retention and release of earlier versions of software shall be managed to enable restoration of a previous known and trusted state when necessary.

3.2.9 The release and installation of software to each submarine shall be appropriately and actively managed so that changes to software are controlled. The installation process shall include a strategy for managing a failed installation.

3.2.10 Assurance of software integrity is to be provided to appropriate standards and verified by an appropriate organisation throughout the entire software lifecycle.

3.2.11 The computer-based system hosting software shall comply with electrotechnical and whole-boat requirements.

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