NEN EN ISO 13849-1 : 2016

Foreword
Introduction
1 Scope
2 Normative references
3 Terms, definitions, symbols and abbreviated terms
   3.1 Terms and definitions
   3.2 Symbols and abbreviated terms
4 Design considerations
   4.1 Safety objectives in design
   4.2 Strategy for risk reduction
       4.2.1 General
       4.2.2 Contribution to the risk reduction by the
             control system
   4.3 Determination of required performance level (PL[r])
   4.4 Design of SRP/CS
   4.5 Evaluation of the achieved performance level PL and
       relationship with SIL
       4.5.1 Performance level PL
       4.5.2 Mean time to dangerous failure of each channel
             (MTTF[d])
       4.5.3 Diagnostic coverage (DC)
       4.5.4 Simplified procedure for estimating PL
   4.6 Software safety requirements
       4.6.1 General
       4.6.2 Safety-related embedded software (SRESW)
       4.6.3 Safety-related application software (SRASW)
       4.6.4 Software-based parameterization
   4.7 Verification that achieved PL meets PL[r]
   4.8 Ergonomic aspects of design
5 Safety functions
   5.1 Specification of safety functions
   5.2 Details of safety functions
       5.2.1 Safety-related stop function
       5.2.2 Manual reset function
       5.2.3 Start/restart function
       5.2.4 Local control function
       5.2.5 Muting function
       5.2.6 Response time
       5.2.7 Safety-related parameters
       5.2.8 Fluctuations, loss and restoration of power
             sources
6 Categories and their relation to MTTF[d] of each channel,
   DC[avg] and CCF
   6.1 General
   6.2 Specifications of categories
       6.2.1 General
       6.2.2 Designated architectures
       6.2.3 Category B
       6.2.4 Category 1
       6.2.5 Category 2
       6.2.6 Category 3
       6.2.7 Category 4
   6.3 Combination of SRP/CS to achieve overall PL
7 Fault consideration, fault exclusion
   7.1 General
   7.2 Fault consideration
   7.3 Fault exclusion
8 Validation
9 Maintenance
10 Technical documentation
11 Information for use
Annex A (informative) Determination of required performance
                      level (PL[r])
Annex B (informative) Block method and safety-related block
                      diagram
Annex C (informative) Calculating or evaluating MTTF[d] values for
                      single components
Annex D (informative) Simplified method for estimating MTTF[d] for
                      each channel
Annex E (informative) Estimates for diagnostic coverage (DC) for
                      functions and modules
Annex F (informative) Estimates for common cause failure (CCF)
Annex G (informative) Systematic failure
Annex H (informative) Example of combination of several
                      safety-related parts of the control
                      system
Annex I (informative) Examples
Annex J (informative) Software
Annex K (informative) Numerical representation of Figure 5
Annex ZA (informative) Relationship between this European Standard
                       and the Essential Requirements of EU
                       Directive 98/37/EC, amended by Directive
                       98/79/EC
Bibliography

Defines safety requirements and guidance on the principles for the design and integration of safety-related parts of control systems (SRP/CS), including the design of software.