functional safety

from Wikipedia, the free encyclopedia

Functional safety (abbreviated also FuSi ) describes that part of the safety of a system that depends on the correct functioning of the safety-related system and other risk-reducing measures. Functional safety does not include electrical safety, fire protection or radiation protection .

overview

Since safety can also be achieved by setting the intended function if necessary and assuming a safe state, one speaks of the safety integrity of the system.

With the complexity of electronic, especially programmable systems, the variety of possible errors increases: Nowadays, microcomputers take over almost all safety functions. For example, they make sure that the pressure in the steam boiler does not exceed the norm; ensure the safety of chemical plants or guide trains onto the right tracks at an appropriate speed. Accordingly, the series of standards IEC 61508 "Functional safety of safety-related electrical / electronic / programmable electronic systems" requires the use of various methods for controlling errors:

  • Avoidance of systematic errors in development, e.g. B. Specification and implementation errors
  • Monitoring during operation to detect random errors
  • Safe control of detected errors and transition to a state previously defined as safe.

Accidental errors can be caused by aging or physical phenomena ( softerror ).

Legal security requirements

Society in general, especially customers and users, have high expectations of the security of systems and the reduction of risks. With the Product Safety Act (ProdSG, until December 2011: GPSG), politicians created a legal framework for the implementation of safety requirements. The avoidance of systematic errors and the control of systematic and random errors in "safety-related functions" reduce the expected risk to an acceptable level.

Important standards of functional safety

The following standards are among the most important regarding functional safety:

  • EN ISO 13849 : Safety of machines - Safety-related parts of control systems
  • EN / IEC 61508 : Functional safety of electrical / electronic / programmable electronic safety-related systems
  • EN / IEC 61511: Functional safety - safety systems for the process industry
  • EN / IEC 62061: Safety of machinery - Functional safety of safety-related electrical, electronic and programmable electronic control systems
  • EN / IEC 50128 : Railway applications - Telecommunications, signaling and data processing systems - Software for railway control and monitoring systems
  • ISO 26262 : Road vehicles - Functional safety

Standard series for motor vehicles: ISO 26262

However, operating errors are not covered by the standards, since the system would then have to assess the manual intervention (“misuse intended by the operator to avoid even greater damage” or “operator error”).

An adaptation of this series of standards for motor vehicles is the ISO 26262 standard ("Road vehicles - Functional safety"). This was first published in November 2011 and was completely revised and republished in December 2018.

Since an ever greater number of electronic components and control units are installed in today's automobiles and the increasing networking of the individual electronic components with one another can be observed, development complexity is increasing steadily. In many markets, approval is therefore subject to legal control in order to comply with the functional safety regulations according to ProdSG .

literature

  • David J. Smith, Kenneth GL Simpson: Functional Safety. A Straightforward Guide to Applying IEC 61508 and Related Standards. 2nd edition. Elsevier / Butterworth-Heinemann, Amsterdam et al. 2004, ISBN 0-7506-6269-7 .
  • Jens Braband: Functional safety. In: Lothar Fendrich (Ed.): Railway Infrastructure Manual. Springer, Berlin et al. 2007, ISBN 978-3-540-29581-5 , pp. 649-699.
  • Peter Löw, Roland Pabst, Erwin Petry: Functional safety in practice. Application of DIN EN 61508 and ISO / DIS 26262 in the development of series products. dpunkt.Verlag, Heidelberg 2010, ISBN 978-3-89864-570-6 .
  • Martin Hillenbrandt: "Functional safety according to ISO 26262 in the concept phase of the development of electrics / electronics architectures for vehicles." KIT Scientific Publishing, Karlsruhe, 2012.
  • Dirk Dürholz, Steffen Herrmann and Ralf Stark: SAFETY Essentials. ISO 26262 at a glance - conveyed in compact form. 2014. ISBN 978-3-9815078-0-5 .

Web links

Individual evidence

  1. ↑ P. Löw, R. Pabst, E. Petry "Functional Safety in Series Products" accessed on August 26, 2014, PDF