PREN ISO 13849-1 : DRAFT 2004

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions and abbreviations
   3.1 Terms and definitions
   3.2 Abbreviations
4 Design considerations
   4.1 Safety objectives in design
   4.2 Strategy for risk reduction
   4.3 Required performance level PL
   4.4 Design and technical realisation of safety functions
   4.5 Determination of the performance level PL and
       relationship to SIL
   4.6 Verification
   4.7 Ergonomic aspects of the design
5 Characteristics of safety functions
   5.1 Specification of safety functions
   5.2 Details on safety functions
6 Categories
   6.1 General
   6.2 Specifications of categories
   6.3 Combination of safety-related parts with different categories
       to achieve an overall PL
7 Fault consideration, fault exclusion
8 Validation
9 Maintenance
10 Technical documentation
11 Information for use
Annex A (informative) Relationship between performance level (PL)
        and categories
Annex B (informative) Designated architectures for safety-related
        parts of control systems
Annex C (informative) Examples of MTTF[d] values for single
        components
Annex D (informative) Simplified method to estimate MTTF[d]
        for each channel
Annex E (informative) Estimates for diagnostic coverage (DC)
Annex F (informative) Estimates for common cause failure (CCF)
Annex G (informative) Systematic failure
Annex H (informative) Combination of several safety-related
        parts of the control system (SRP/CS)
Annex I (informative) Examples
Annex ZA (informative) Relationship between this European
         Standard and the Essential Requirements of EU Directive
         (Directive 98/37/EC of the European Parliament and of the
         council of 22 June 1998 on the approximation of the
         laws of the member states relating to machinery)
Bibliography

Provides safety requirements and guidance on the principles for the design of safety-related parts of control systems (SRP/CS).