PD CLC/TR 50506-2:2009

Introduction
1 Scope
2 References
3 Terms, definitions, symbols and abbreviated terms
4 Safety design for signalling subsystems
5 Safety case structure in relation with associated
  documents and activities
6 Safety assessment and approval
Annex A (informative) - EN/IEC standards for safety
        analysis
Annex B (informative) - Documentation for approval
Annex C (informative) - Structure of the System
        Requirements Specification
Bibliography

Describes the preparation of a safety case, enhancing points providing the required evidence for safety assessment and approval.

This document is a Technical Report about the basic standard. It is applicable to the same systems and addresses the same audience as the standard itself. It enhances information on specific items on the application of EN 50129. The following items are covered, within the scope of this Application Guideline of EN 50129, as follows:

• Clause 4 deals with identification and mitigation of failures in the concept, specification and design phases. It is mainly dedicated to designers and verifiers and product safety engineers;

• Clause 5 deals with the preparation of a safety case, enhancing points providing the required evidence for safety assessment and approval. It is mainly dedicated to verifiers, validators, safety managers, quality managers and safety engineers;

• Clause 6 deals with the activities an Independent Safety Assessor has to carry out. It is mainly dedicated to safety assessors, safety authorities, safety managers and safety approvals.

In drafting this guidance, it is assumed that the reader is familiar with the basic structure of the standard.

This document does not claim to be exhaustive. It is not a complete compilation of best practices, but only the translation of the knowledge of all the experts of the Working Group in charge of composition of this Application Guideline.