Software Dependability: A Personal View

This paper attempts to stand back and consider how the field o f software dependability research has progressed over the last twenty-five or so years. It provides a personal perspective on early developments such as the recovery block and the Nversion programming scheme, and on more recent research in which the author has been involved aimed at unifying and extending these schemes. It then discusses first the present state of the art and then the way that the industry is likely to develop in future and the consequences this will have on the dependability field. This discussion draws on a summary o f some of the ideas that were put forward at a recent ICL/ESPRITsponsored workshop that the author helped to organize. This workshop was in fact on The Future of the Software Industry. However, a number of the ideas discussed, in particular those relating to mega-systems and to system structuring, are o f particular relevance to software dependability research.