7.17 Deactivation or Processing
Note;This stage is Box 16 of Figure 2.
7.17.1 Purpose
Guarantee the functional safety of the EPE safety-related systems during the deactivation or processing of the EUC, and after the event.
7.17.2 Requirements
7.17.2.1An impact analysis shall be carried out prior to the decommissioning or treatment activity, which shall include an impact assessment of the proposed decommissioning or processing activity on the functional safety of any E E PE safety-related system and its associated EUC, and shall also take into account the adjacent EUC and the impact on the E E PE safety-related system. The assessment includes a hazard and risk analysis that determines the breadth and depth of the hazards and risks to be assumed at each stage of the subsequent security lifecycle, the e-pes security lifecycle or the software security lifecycle.
7.17.2.2 7.17.2.1 The stated results should be documented.
7.17.2.3 In accordance with the functional safety management procedures, the decommissioning and processing phase can only be initiated after an approved request has been issued (see Chapter 6).
7.17.2.4 Approval to carry out the required deactivation or processing depends on the results of the impact analysis.
7.17.2.5 A plan should be developed prior to decommissioning or disposal, which includes the following procedures:
e e pe closure of safety-related systems;
e e e pe dismantling of safety-related systems.
7.17.2.6 If the decommissioning or processing activities would have an impact on the functional safety of the E e PE safety-related systems, the initiation execution activities will be returned to the appropriate stage of the overall safety life cycle, the E e PES safety life cycle or the software safety life cycle. All subsequent phases are then carried out in accordance with the relevant procedures for the safety integrity levels specified in GB T 20438 for E e PE safety-related systems.
NOTE 1: It may be necessary to carry out a comprehensive hazard and risk analysis, which requires a different safety integrity level for the E e PE safety-related system.
Note 2: The functional safety requirements in the decommissioning or processing phase may differ from those in the operational phase.
7.17.2.7 Chronological documentation including details of deactivation and processing activities shall be established and maintained, including:
Plans for deactivating or processing activities
Impact analysis. 7.18 Validation
7.18.1 Purpose
Through review, analysis and (or testing) to demonstrate that the output of each phase of the overall security life cycle, the E e PES security life cycle and the software security life cycle fully meets the requirements and objectives specified in each phase.
7.18.2 Requirements
7.18.2.1 For each phase of the overall security lifecycle, the e-pes security lifecycle and the software security lifecycle, a validation plan should be established at the same time as the development of the phase.
7.18.2.2 The verification plan should compile or refer to the guidelines, techniques, and tools used in the verification activities.
7.18.2.3 Verification should be carried out according to the verification plan.
Note: The choice of validation techniques and measures, as well as the degree of independence of validation activities, depends on a number of factors and may be specified in the standards for the field of application.
Examples of these factors are:
Project scale;Level of complexity;
The degree of novelty of the design;
The degree of novelty of the technology.
7.18.2.4 Information on validation activities should be collected and documented as evidence that the validation phase has been fully and successfully completed.