Accounting for Evidence: Managing Evidence for Goal Based Software Safety Standards
Goal-based safety standards require an evidence-based approach from suppliers and the large volume of evidence for safety assurance that is generated by a software project needs to be effectively assessed and managed. A structured safety argument needs to be created and agreed with regulators and other stakeholders early in the project lifecycle so that project processes can be designed to produce the required evidence. This safety argument needs to be abstracted in that it should define the requirements for evidence without attempting to explicitly identify the concrete evidence generated. A means of traceability between abstract requirements for evidence and concrete realization needs to be provided: an SQL database which can be hyperlinked to the argument is an efficient means of managing both the status of evidence and the traceability to the argument. The safety case is completed once the evidence has been successfully generated and assessed by an evidence report in which the assessment of limitations in evidence and counter-evidence can be effectively managed.
KeywordsObject Management Group Safety Engineer Safety Case Safety Management System Defence Standard
Unable to display preview. Download preview PDF.
The author gratefully acknowledges the discussions on safety arguments and insight into the SAEM provided by Dr Tim Kelly, University of York.
- Adelard (1998) ASCAD – Adelard safety case development manualGoogle Scholar
- Civil Aviation Authority (2010) CAP 670 ATS safety requirementsGoogle Scholar
- European Commission (2008) Commission Regulation (EC) No 482/2008 Establishing a soft-ware safety assurance system to be implemented by air navigation service providers and amending annex II to regulation (EC) No 2096/2005 http://www.caa.co.uk/docs/952/SESESARR%28482-2008%29.pdf. Accessed 12 September 2010
- Hamilton V (2006) Criteria for safety evidence – goal-based standards require evidence based approaches. Safety Systems 16:1 September 2006. http://www.vivhamilton.co.uk/Papers/SCEvCriteria.pdf. Accessed 12 September 2010
- IEC (2000) ISO/IEC 61508 Functional safety of electrical/electronic/programmable electronic safety related systems, Parts 1 to 7. International Electrotechnical CommissionGoogle Scholar
- Kelly T (1999) Arguing safety – a systematic approach to safety case management. PhD thesis, University of York YCST99/05Google Scholar
- Menon C, Hawkins R, McDermid J, Kelly T (2010) An overview of the SOBP for software in the context of DS 00-56 issue 4. In: Dale C, Anderson T (eds) Making systems safer. Springer-Verlag, LondonGoogle Scholar
- Ministry of Defence (2007) Defence Standard 00-56 Issue 4: Safety management requirements for defence systemsGoogle Scholar
- Object Management Group (2010) Software assurance evidence metamodel (SAEM) Sysa/10-02-01 http://www.omg.org/cgi-bin/doc?sysa/10-02-01. Accessed 23 March 2010
- RTCA (1992) RTCA/DO-178B: Software considerations in airborne systems an equipment certification. RTCAGoogle Scholar