Engineering reliable software

Software reliability engineering is not only the use of software reliability models and similar techniques, it is the use of sensible engineering principles with cost/benefit analysis throughout the software life cycle to obtain reliable software. The need to have a comprehensive view on software development to engineer reliable software is emphasized. Cleanroom Software Engineering is proposed as being the basis for developing reliable software. The paper in particular discusses some extensions to Cleanroom, both in terms of adaptations and additions. Particular emphasis is on high-level design techniques and methods for reliability certification of the software. The comprehensive view of software is supported by several success stores, both with references to results presented in literature as well as experiences from projects conducted by Q-Labs. The results obtained are encouraging. The methods proposed are shown to give a substantial gain in the development of reliable software