Functional safety in machinery - EN 13849-1 - Safety-related parts of control systems

NF EN ISO 13849-1 October 2008

Safety of machinery

Safety-related parts of control systems — Part 1: General principles for design


D : D : Sicherheit von Maschinen — Sicherheitsbezogene Teile von Steuerungen — Teil 1 : Allgemeine Gestaltungsleitsätz

ISO 13849 standard comprises several parts:

  • Part 1: General principles for design
  • Part 2: Validation
  • Part 100: Guidelines for the use and application of ISO 13849-1 [Technical Report]

Parts 1 and 2 of the standard are harmonized standards under the Machinery Directive 2006/42/EC standards.

Contents of EN 13849-1 standard

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 (PLr)
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 (MTTFd)
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 PLr
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 MTTFd of each channel, DCavg 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 (PLr)
Annex B (informative) Block method and safety-related block diagram
Annex C (informative) Calculating or evaluating MTTFd values for single components
Annex D (informative) Simplified method for estimating MTTFd 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