Small Modules as Configuration Items in Certified Safety Critical Systems

Abstract

All systems should be delivered to the customer as correctly functioning and resilient products of sound design and manufacturing processes. For dependable systems this is a requirement that is getting harder to prove the more we begin to rely on programmable electronics to control processes or systems where Safety and Security is paramount. Appropriate modularity, well defined interfaces and tight configuration management are just some of the tools we can use to ensure that the right product, certified for compliance with customer, statutory and integrity requirements is delivered.

A lot has been spoken and written on the subject of analysing the integrity requirements for a system. We have, over previous years, heard of HAZOPs risk analysis, formal methods, code checking tools etc. We have talked through various different lifecycle models and discussed their impact on project timescales. A couple of subjects seem to have been left more or less alone. These are the subjects of configuration management and decompositional modularisation. This paper seeks to re-dress the balance a little and to show how these two subjects interact.