Five Decades of Software Reliability, Past, Present, Future and New Challenges

Almost 50 years have passed since the first Software Reliability models were developed, namely the well-known nonhomogeneous Poisson processes based. Over these years, a lot of new models have been proposed and software component has become more and more important in technological projects. In addition, and perhaps more importantly, Software Engineering has strongly evolved and so have software development and testing methodologies, improving the classical waterfall method popular in the 70s. This poses some questions: Are the original models still applicable? Are there any software reliability models that take into account modern Software Engineering methodologies? What are the new concepts introduced by the modern Software Engineering methods? What are the new characteristics required to Software Reliability models in order to be applied to todays projects? In this paper, we address these questions by reviewing the academic and industrial research on Software Reliability and Engineering and analyze possible new proposals.