Risk analysis techniques and their application to software development

The past decade has seen a dramatic change in the emphasis of software to hardware. Whereas a project may have comprised 80% hardware and 20% software, the reverse is now generally more realistic. This has resulted in a great deal of interest focusing around the areas of quality metrics and reliability growth applied to the software lifecycle. Risk analysis has to date seen many applications in the assessment of hardware but little in the software area. This paper reviews the risk analysis techniques that have been developed in a range of industries. Progress in this area has been most apparent in the chemical and nuclear power industries where probabilistic risk assessment has been used to estimate the total risk associated with the whole plant. A discussion of the appropriateness of the techniques to software safety assessment is included together with an outline of the methods currently being used to detect software faults. Suggestions are made for a new methodology in analysing software safety.