Section 2 Context

2.1.1 The following general model of responsibilities is assumed for Engineering System procurement, see Figure 1.2.1 Software Rules process diagram

1. System level – responsible for specifying, procuring, integrating and implementing Engineering Systems within the ship;
2. Engineering System level – responsible for delivering a specific Engineering System including specifying, procuring, and integrating its separate elements (which might include software), delivering the Engineering System, and supporting system level activities as necessary;
3. Software level – responsible for implementing and delivering a software element of an Engineering System, and supporting higher level activities as necessary.

Figure 1.2.1 Software Rules process diagram

2.1.2 The responsibility for integrating a Software Product with the target hardware is to be agreed between the Engineering System level and the Software level as part of any contract or other statement of works. Irrespective of who has responsibilities, the relevant requirements of these Rules are applicable.

2.1.3 Identification of Relevant Hazards and associated Relevant Hazard Requirements is to use appropriate analysis techniques involving risk assessment. Relevant Hazard Requirements can be specified by reference to recognised National or International Standards such as IEC/ISO 31010 Risk Management – Risk Assessment techniques, or similar, acceptable to LR. In such cases, it should be demonstrated that all Relevant Hazards are addressed for the specific application. The Relevant Hazards and their causes are to be identified at the System level and/or the Engineering System level.

2.1.4 There is to be a documented process that results in verified Relevant Hazard Requirements being defined for the Software Product.

2.1.5 Although not always the case, typically the whole ship is regarded as a System comprising one or more Engineering Systems, any of which may contain one or more separately delivered Software Products. When the System includes features provided by elements external to the vessel the scope of the System is to include those external elements. Functionality may be distributed across multiple Engineering Systems.

2.1.6 The word ‘software’ refers to the specific Software Product which is subject to appraisal against these Rules. If more than one Software Product is proposed to implement an Engineering System, each Software Product is to have requirements specified separately under these Rules. Before there is any realisation of a Software Product, the word ‘software’ refers to the intended Software Product.

2.1.7 Where multiple Software Products are used for the implementation of one Engineering System, the Engineering System level organisation is responsible for their integration. In such cases, the Engineering System level organisation is considered to be a Producer of Software and is therefore to comply with the requirements of these Rules as applicable to the reduced scope of its activities. Where the reduced scope leads to derogations of the Rules, they are be agreed with LR at the earliest practicable stage in the Production of Software, and at least prior to the end of the requirement specification stage.