Safety Cases for Software Application Reuse
In traditional engineering industries it is common to reuse tried and trusted components as one of the means of ensuring safety. Some low-level software components, e.g. libraries, are reused, but there are difficulties in justifying the reuse of software due to the complexity of interactions in a typical software system. This paper addresses the issue of reusing software applications by considering how to extend the safety case for the use of software in one application based on its use in another. It proposes an approach to analysing the change between two contexts of use of a software system, including analysing small changes in the software, and illustrates this through some examples based on an analysis of a reactor protection system.
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