Understanding the Redundancy of Software Systems

Our research aims to study and characterize the redundancy of software systems. Intuitively, a software is redundant when it can perform the same functionality in different ways. Researches have successfully defined several techniques that exploit various form of redundancy, for example for tolerating failures at runtime and for testing purposes. We aim to formalize and study the redundancy of software systems in general. In particular, we are interested in the intrinsic redundancy of software systems, that is a form of undocumented redundancy present in software systems as consequence of various design and implementation decisions. In this thesis we will formalize the intuitive notion of redundancy. On the basis of such formalization, we will investigate the pervasiveness and the fundamental characteristics of the intrinsic redundancy of software systems. We will study the nature, the origin, and various forms of such redundancy. We will also develop techniques to automatically identify the intrinsic redundancy of software systems.