Perspectives on Redundancy: Applications to Software Certification

Redundancy is a feature of systems that arises by design or as an accidental byproduct of design, and can be used to detect, diagnose or correct errors that occur in systems operations. While it is usually investigated in the context of fault tolerance, one can argue that it is in fact an intrinsic feature of a system that can be analyzed on its own without reference to any fault tolerance capability. In this paper, we submit three alternative views of redundancy, which we propose to analyze to gain a better understanding of redundancy; we also explore means to use this understanding to enhance the design of fault tolerant systems.