Challenges facing Software Fault-tolerance

Abstract

As software dominates most discussions in the information technology business, one needs to carefully examine where we are headed in software dependability. This paper re-examines some of the basic premises upon which the area of software fault-tolerance is built and critiques some current practices and beliefs. A few of the thoughts and contributions are: The de nition of a software failure needs to change from a speci cation based thought to one of customer expectation and ability to do productive work. This will cause a signi cant shift on what we build fault-tolerance for. However, it would also help narrow the gap between today's theory, practice and customer need. Data on customer problems illustrates that 90 % of the problems reported are what we have traditionally considered as non-defect { implying no need for a programming change. However, with the new de nition of failure, we will need to address this more seriously as a part of fault-tolerance. This change could level the playing eld and help achieve greater customer satisfaction. A rationale for determining the amount of fault-tolerance based on the concept of th