Safety Cases for Software-Intensive Systems
In most industries, best practice for software and systems that use software is to provide a detailed written argument for product safety, that is, a Safety Case.
The implementation of system functions by software represents some unique risks to safety. Flexible programming languages and powerful microprocessors provide an inexpensive and flexible means for introducing complexity, and in safety-related projects this can significantly increase the time, resources and cost involved in producing a Safety Case for the system.
This paper introduces an approach to Safety Cases which has been successfully applied on a number of projects by Praxis Critical Systems. We believe it provides strong, clear Safety Cases for software-intensive systems and at the same time brings significant cost benefits to developing them.
KeywordsHazard Analysis Safety Management Safety Requirement Risk Assessment Process Safety Case
Unable to display preview. Download preview PDF.
- [Ainsworth 1999]M Ainsworth and AJ Simpson: Integrated Modular Avionics — A View on Safe Partitioning, In Towards System Safety, ed. F Redmill and T Anderson, Springer-Verlag, 1999.Google Scholar
- [Barnes 1997]John Barnes and Praxis Critical Systems: High Integrity Ada: The Spark Approach, Addison Wesley, 1997.Google Scholar
- [CENELEC 1998]CENELEC: Railway Applications – Safety Related Electronic Systems for Signalling, ENV 50129, 1998.Google Scholar
- [DefAust 1998]Australian Defence Standard, The Procurement of Computer-Based Safety Critical Systems, Def(Aust) 5679, Army Standardisation (AEA), 1998.Google Scholar
- [DERA 1998]Defence Evaluation and Research Agency: Guidance for the provision of an aircraft Safety Case, Boscombe Down, DERA/AT&E/MC/TR0005/1.0, Issue 1, March 1998.Google Scholar
- [Railtrack 2000]Railtrack: Yellow Book 3, Engineering Safety Management, Issue 3, 2000.Google Scholar
- [Simpson 1999]AJ Simpson and M Ainsworth: White Box Safety, in Proc. 1999 Avionics Conference, ERA Report 99–0815, ERA Technology Ltd, 1999.Google Scholar
- [UK MOD 1996]UK Ministry Of Defence: Safety Management Requirements for Defence Systems, Defence Standard 00–56, Issue 2, 1996.Google Scholar