Guidance for Use of CSM Recommendation - ERA - Europa

European Railway Agency
Collection of examples of risk assessments and of some possible tools
supporting the CSM Regulation
3. DEMONSTRATION OF COMPLIANCE WITH SAFETY
REQUIREMENTS
3.1. Prior to the safety acceptance of the change, fulfilment of the safety requirements
resulting from the risk assessment phase shall be demonstrated under the supervision
of the proposer.
[G 1] As explained in points [G 3] to [G 6] in section 2.1.1, the "demonstration of the system
compliance with the safety requirements" includes the phases "6 to 10" of the CENELEC V-
Cycle (see BOX 3 in Figure 5). Refer to point [G 3] in section 2.1.1.
[G 2] Refer also to point [G 4] in section 2.1.1 of this document.
3.2. This demonstration shall be carried out by each of the actors responsible for fulfilling
the safety requirements, as decided in accordance with point 1.1.5.
[G 1] An example of safety assessments and safety analyses that can be performed at the subsystem
level are causal analyses: see Figure 10. But any other method can be used to
demonstrate the sub-system compliance with the input safety requirements.
Cause (of a Hazard at System Level)
Hazard (at Sub-System Level)
Hazard (at System Level)
Accident k
Accident l
Cause (of a
Hazard at Sub-
System Level)
Sub-System
Boundary
System Boundary
CAUSES
CONSEQUENCES
Figure 10 : Figure A.4 of EN 50 129:
Definition of hazards with respect to the system boundary.
[G 2] The hierarchical structuring of hazards and causes, with respect to systems and subsystems,
can be repeated for each lower level phase of the CENELEC V-Cycle in Figure 5,
The hazard identification and causal analysis activities (or any relevant method), as well as
the use of codes of practice, similar reference systems and explicit analyses and
evaluations, can also be repeated for each phase of the system development cycle in order
to derive, from the safety measures identified at the sub-system level, the safety
requirements to be fulfilled by the next phase. This is illustrated in Figure 11.
[G 3] Refer also to point [G 4] in section 2.1.1 of this document.
Reference: ERA/GUI/02-2008/SAF Version: 1.1 Page 48 of 105
File Name: Collection_of_RA_Ex_and_some_tools_for_CSM_V1.1.doc
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